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For driving or controlling laser

Subclass of:

372 - Coherent light generators

372380100 - PARTICULAR COMPONENT CIRCUITRY

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DocumentTitleDate
20110002350METHOD OF CONTROLLING A DIODE DEVICE FOR USE IN OPTICAL STORAGE SYSTEMS - A system and method is provided which compensates for the effects of relaxation oscillations and turn-on delays of diode laser devices. In particular, there is provided a method and system for tuning the shape of the power profile of an output optical signal and its position with respect to a channel bit clock of an optical recording system.01-06-2011
20130044778OPTICAL SOURCES HAVING A CAVITY-MATCHED EXTERNAL CAVITY - An optical source including a laser source and a waveguide is provided. The laser source includes a laser cavity having a laser optical path length extending from a DBR grating to a reflective laser output facet, and emits an output beam at a fundamental wavelength. The waveguide includes an input facet and an output face. The waveguide extends along a waveguide optical length from the input facet of the waveguide to the output facet of the waveguide, and the waveguide is optically coupled to the laser source, thereby forming an external cavity having an optical path length extending from the reflective laser output facet to the input facet of the waveguide that is substantially equal to the laser optical path length.02-21-2013
20100158061Color-Controlled Illumination Device - The invention relates to a color-controlled illumination device (06-24-2010
20100061413Laser Driver Circuit and Laser Display - A laser driver circuit comprising a current supply circuit for supplying a laser diode with a current is provided. The current supply circuit comprises a voltage-to-current converter circuit, a current output line for outputting the current generated by the voltage-to-current converter circuit, a current supply line connected to the laser diode, a ground line connected to the ground, and a current path switch for selectively connecting either the current supply line or the ground line to the current output line. The laser driver circuit further comprises a current output prevention circuit for preventing the voltage-to-current converter circuit from generating the current by disconnecting the voltage input line using a voltage input switch so that the voltage is not input to the voltage-to-current converter circuit, when the current output line and the ground line are connected by the current path switch.03-11-2010
20080259979PROVIDING A SUITABLE OUTPUT CURRENT TO A LASER DIODE - A laser diode driving circuit capable of providing a suitable output current to a laser diode is disclosed. The laser diode driving circuit includes a current supply, a first pseudo laser diode, a second pseudo laser diode, and an output current mirror circuit. An input current provided by the current supply is output through the output current mirror circuit to the laser diode. By making the characteristic of each of the first and second pseudo laser diodes substantially equal to the characteristic of the laser diode, the non-linearity between the input current and the output current is compensated.10-23-2008
20090034565CURRENT DRIVE CIRCUIT - A current drive circuit according to the present invention includes: a first current source and a second current source (I02-05-2009
20130083817LASER DEVICE - A laser device that can prevent abnormal oscillations in the amplifier is provided.04-04-2013
20090190620OPTICAL DISK DEVICE AND METHOD OF CONTROLLING LIGHT EMITTING ELEMENT - An optical disk device includes: a light emitting element which applies light to an optical disk; a light detection unit which receives the light emitted from the light emitting element and outputs an intensity signal corresponding to an intensity of the light emitting element; a difference detection unit which generates a control signal based on a difference between the intensity signal and a reference intensity signal; a first current supply unit which supplies a first current based on the control signal; a second current supply unit which supplies a second current; a current adding unit which adds the first and second currents to generate a third current and supplies the third current to the light emitting element; an optical pickup on which the first current supply unit and the adding unit are placed; and a circuit board on which the second current supply unit is placed.07-30-2009
20130077646AUTOMATIC MODULATION CONTROL FOR MAINTAINING CONSTANT EXTINCTION RATIO (ER), OR CONSTANT OPTICAL MODULATION AMPLITUDE (OMA) IN AN OPTICAL TRANSCEIVER - To a laser that has no tracking error a desired laser modulation current to maintain constant Optical Modulation Amplitude (OMA) is closely proportional to the laser bias current, lb, at any temperature when the laser is under constant power according to embodiments. To a laser that has tracking error a desired laser modulation current to maintain constant Optical Extension Ratio (ER) is closely proportional to the laser bias current, lb, at any temperature when the laser is under constant power according to embodiments. This phenomenon is appears apply to many if not all types of lasers. A laser modulation control is provided that determines a modulation current based on the laser bias current. Thus, embodiments may maintain performance and compensate for temperature changes without the need to actually measure temperature thereby eliminating the need for temperature sensors and their associated parameter vs. temperature look-up tables or dithering techniques used in the past.03-28-2013
20130039373LASER DIODE READ DRIVER - A laser diode read driver includes a first transistor producing a first voltage in response to receiving a first current signal. A transconductor has a first input coupled to receive the first voltage and produces a second current signal in response to differences between signals received on the first input and a second input. A second transistor is coupled to the second input and produces a third current signal in response to receiving the second current signal. A third transistor is coupled to the second transistor and the second input and produces an output current signal in response to receiving the third current signal. The first transistor is scaled to the first transistor by the inverse of a gain factor. First and second resistors are coupled between the first and third transistors and a low voltage supply, and are scaled to each other by the gain factor.02-14-2013
20100027573METHOD OF DRIVING A LASER DIODE - An ultrashort pulse/ultra-high power laser diode with a simple structure and configuration is provided. In a method of driving a laser diode, the laser diode is driven by a pulse current which is 10 or more times higher than a threshold current value. The width of the pulse current is preferably 10 nanoseconds or less, and the value of the pulse current is specifically 0.4 amperes or over.02-04-2010
20130051415HIGH-EFFICIENCY, DUAL CURRENT SINK LASER DIODE DRIVER - Provided are assemblies and processes for activating light emitting devices. A first current sink is in electrical communication with a common source through a current node and configured to draw a first current through the current node in response to a respective control signal. A second current sink is also provided in electrical communication with the current node and in parallel with the first current sink, also configured to draw a second current through the current node in response to a respective control signal. An aggregate current is drawn through the array, determined as a combination of the first and second currents. A commanded current from the first current sink can be shunted around the second array and the second current sink, providing a capability to series both the first and second laser diode light-emitting arrays, while simultaneously drawing different current amplitudes through each array from a common potential source.02-28-2013
20120219029Pulsed-Multiline Excitation for Color-Blind Fluorescence Detection - The present invention provides a technology called Pulse-Multiline Excitation or PME. This technology provides a novel approach to fluorescence detection with application for high-throughput identification of informative SNPs, which could lead to more accurate diagnosis of inherited disease, better prognosis of risk susceptibilities, or identification of sporadic mutations. The PME technology has two main advantages that significantly increase fluorescence sensitivity: (1) optimal excitation of all fluorophores in the genomic assay and (2) “color-blind” detection, which collects considerably more light than standard wavelength resolved detection. Successful implementation of the PME technology will have broad application for routine usage in clinical diagnostics, forensics, and general sequencing methodologies and will have the capability, flexibility, and portability of targeted sequence variation assays for a large majority of the population.08-30-2012
20130058368LASER DRIVER - An apparatus is provided. The apparatus includes a lasing element, a laser driver and logic. The laser driver is configured to drive the lasing element at multiple current levels, and the laser driver includes a switching network, multiple direct current (DC) loops, and an output circuit. The switching network receives a differential input signal, and each DC loop is coupled to the switching network. The output circuit is also coupled to the lasing element, and the logic is coupled to each of the DC current loops, where the logic selects one or more of the DC loops in each (of several) modes. Each mode generates one or more output lasing currents for the lasing element that corresponds to a one or more of the current levels in response to the differential input signal.03-07-2013
20090268767DC COUPLED DRIVER WITH ACTIVE TERMINATION - A DC coupled driver is described for modulating a vertical cavity surface emitting laser at high speeds with active termination. High speed and low total power dissipation is achieved by improving the driver immunity to pulse reflections, which can arise due to impedance mismatch between the driver output impedance and the VCSEL impedance. The rise and fall times of the driver may be adjusted for particular applications. The driver may be fabricated using a choice of bipolar, NMOS and PMOS technologies.10-29-2009
20090268766OPTICAL TRANSMITTER APPLICABLE TO BURST SIGNAL AND METHOD FOR CONTROLLING THE SAME - An optical transmitter and a method to control the transmitter are disclosed, in which the optical output may be substantially maintained even in the inactive state of the input burst signal. The optical transmitter includes the APC feedback control and the detector that senses the active and inactive states of the input burst signal. When the transition to the inactive state is detected, the controller enters the second APC mode in which only the bias current is adjusted so as to maintain the optical output to be a preset value. The normal APC feedback control may be recovered after a preset period from the practical transition of the input burst signal from the inactive state to the active state.10-29-2009
20090238226DRIVER CIRCUIT FOR SEMICONDUCTOR LASER DIODE DRIVEN IN DIFFERENTIAL MODE - A driver circuit for a semiconductor laser diode (LD) is disclosed, in which the driver circuit drives the LD in the differential mode and lowers the power consumption thereof. The driver circuit includes a differential unit to provide the modulation current to the LD, a voltage converter to provide a positive power supply to the differential unit, a detector to detect the common mode voltage of the differential outputs of the unit, and a comparing unit to control the voltage converter dynamically such that the output common mode voltage is set in a preset reference level.09-24-2009
20090232175DRIVE CIRCUIT FOR SEMICONDUCTOR LIGHT EMITTING ELEMENT, AND LIGHT SOURCE DEVICE, LIGHTING DEVICE, MONITOR DEVICE, AND IMAGE DISPLAY DEVICE USING THE DRIVE CIRCUIT - A drive circuit for a semiconductor light emitting element used for a light source device adapted to output a laser beam converted using a wavelength conversion element adapted to generate a second harmonic wave, includes a switching element connected to a power supply, an inductor having one end connected to the power supply via the switching element, and the other end connected to the ground, a first terminal disposed between the switching element and the inductor, to which a cathode terminal of the semiconductor light emitting element is connected, and a second terminal disposed between the other terminal of the inductor and the ground, to which an anode terminal of the semiconductor light emitting element is connected.09-17-2009
20090232174SEMICONDUCTOR LASER DRIVING DEVICE AND SEMICONDUCTOR LASER DRIVING METHOD - A semiconductor laser driving device is mounted on an information recording/reproducing device or the like, and is suitably used for recording and reproducing information. The semiconductor laser driving device is provided with a semiconductor laser for emitting laser beams, and a temperature detecting means for detecting a temperature of the semiconductor laser, and changes an output of the laser beams based on the detected temperature. Thus, the semiconductor laser driving means can suitably improve response characteristics of the semiconductor laser, irrespective of the temperature of the semiconductor laser. Therefore, the semiconductor laser driving device can ensure recording performance to an optical disc without being affected by the temperature of the semiconductor laser.09-17-2009
20090010289LASER CIRCUIT SUBSTRATE - This invention makes it possible to meet a requirement of high-quality image printing and high-speed driving of a semiconductor laser driver in a laser beam printer or the like while suppressing radiant noise. A laser circuit substrate includes a first wiring pattern and second wiring pattern connected to a main wiring pattern, a first circuit which is connected to the first wiring pattern and has a semiconductor laser element and a driving circuit for driving the semiconductor laser element, a second circuit which is connected to the second wiring pattern and compensates noise generated by the first circuit, a first capacitor which is connected to a first point in the first wiring pattern, and a second capacitor which is connected to a second point in the second wiring pattern. The positions of the first point and second point are set such that the sum of the impedances of the first wiring pattern and first circuit viewed from the first point, and the sum of the impedances of the second wiring pattern and second circuit viewed from the second point are substantially equal to each other.01-08-2009
20120113999DRIVER FOR LASER DIODE IMPLEMENTED WITH OFFSET CONTROL - A driver circuit for an LD is disclosed. The circuit includes a decision unit, an offset adjustor, and an amplifier each having the differential configuration in an embodiment. The decision unit decides and generates a signal LOS that distinguishes the existence/absence of the input signal. The offset adjustor, depending on the signal from the decision unit, adds/compensate the offset thereof. The amplifier, whose output are pulled up to the power supply Vcc through an inductor. Because the output of the offset adjustor compensates the offset thereof during the absence of the input signal, the output of the amplifier does not cause overshoot or undershoot.05-10-2012
20120236888METHOD TO DRIVE SEMICONDUCTOR LASER DIODE - A method or algorithm to control a driving current supplied to a semiconductor laser diode (LD) is disclosed. the method first prepares the look-up-table (LUT) that stores a set of parameters, α and β, for evaluating the modulation current Im by the equation of Im=α×Ib+β, where Ib is determined by the auto-power-control (APC) loop. In a practical operation of the LD, the APC loop determines Ib, while, Im is calculated according to the equation above by reading above two parameters corresponding to the current temperature of the LD from the LUT.09-20-2012
20120236887OPTICAL PICKUP APPARATUS, INTEGRATED CIRCUIT, AND METHOD FOR CONTROLLING LASER OUTPUT OF OPTICAL PICKUP APPARATUS - An optical-pickup apparatus includes: a first laser light source including a first laser diode to emit a laser beam having a first wavelength, and a back-monitor photodetector to receive the laser beam emitted in a backward direction, not being an optical-disc direction, and output a first monitor signal; a second laser-light source including a second laser diode to emit a laser beam having a second wavelength; a light-receiving circuit including a front-monitor photodetector to receive the laser beam emitted in a forward direction, being the optical-disc direction, and output a second monitor signal, and a switch circuit to be inputted with the first and second monitor signals, and output the first or second monitor signal according to a switch signal; and first and second drive circuits to drive the first and second laser diodes according to the first and second monitor signals outputted from the light-receiving circuit, respectively.09-20-2012
20110280265DRIVER CIRCUIT FOR THE DIRECT MODULATION OF A LASER DIODE - A driver circuit for a laser diode provides drive signals to the electrodes of the laser diode based on a pulsed input signal. An input receives the pulsed input signal and launches it into an amplification stage which preferably includes dual amplifiers, a buffering stage and a biasing stage. The output of the laser diode is an optical signal that reproduces the pulsed input signal with high fidelity and low amplitude noise. In one embodiment, the input separates the pulsed input signal into two signal components, launched in respective inverting and non-inverting branches which each include successive amplification, buffering and biasing stages.11-17-2011
20100034226LASER DRIVER CIRCUIT, METHOD FOR CONTROLLING A LASER DRIVER CIRCUIT, AND USE - A laser driver circuit comprising an amplifier device with a plurality of switchable subamplifiers, which can be or are connected to an output for connection of a laser, ith an analog switching device for switching of analog input signals, a plurality of analog inputs for the analog input signals, a plurality of control inputs for receiving digital control signals, wherein each switchable subamplifier has a switching device for switching the amplification by one of the digital control signals, a digital switching device connected to an input of each switching device for the selectable connection of the input of the switching device of each switchable subamplifier to a control input. Whereby each switchable subamplifier has an analog input, which is connected to the analog switching device for the selectable switching of an analog input signal to the analog input.02-11-2010
20090296763LIGHT OUTPUT DEVICE AND IMAGE FORMING APPARATUS INCLUDING THE LIGHT OUTPUT DEVICE - A light output device includes: an output unit including a light source; a control voltage generation unit that detects output power of the light source, and generates a control voltage for controlling a drive current of the light source; a control unit that sets a target value of the output power; a voltage-current conversion unit that converts the control voltage into the drive current; a setting unit that sets an inclination of a characteristic line of control voltage-drive current conversion in the voltage-current conversion unit; and an adjustment unit that adjusts the voltage-current conversion unit such that the drive current becomes a target current value for setting the output power to the target value in a predetermined control voltage value on the characteristic line, wherein the setting unit sets the inclination of the characteristic line to a first inclination where the drive current does not reach a maximum current value.12-03-2009
20120236886LASER DIODE ELEMENT ASSEMBLY AND METHOD OF DRIVING THE SAME - A laser diode element assembly includes: a laser diode element; and a light reflector, in which the laser diode element includes (a) a laminate structure body configured by laminating, in order, a first compound semiconductor layer of a first conductivity type made of a GaN-based compound semiconductor, a third compound semiconductor layer made of a GaN-based compound semiconductor and including a light emission region, and a second compound semiconductor layer of a second conductivity type made of a GaN-based compound semiconductor, the second conductivity type being different from the first conductivity type, (b) a second electrode formed on the second compound semiconductor layer, and (c) a first electrode electrically connected to the first compound semiconductor layer, the laminate structure body includes a ridge stripe structure, and a minimum width W09-20-2012
20090052485LASER DRIVING CIRCUIT - A purpose of this invention is to suppress radiation noise while satisfying demands for higher speeds and higher image qualities of a semiconductor laser driving device in a laser beam printer or the like. A laser driving circuit includes a first wiring pattern and a second wiring pattern which are connected to a main wiring pattern, a first circuit which is connected to the first wiring pattern and has a semiconductor laser element (02-26-2009
20080267235Laser10-30-2008
20090310636LIGHT INTENSITY BOOST FOR SUBPIXEL ENHANCEMENT - Techniques are disclosed that enable fine features such as serifs and narrow strokes of texts to be produced by xerographic devices, for example. The fine features may be generated by subpixels which are produced when a pulse width used to image a pixel is shorter than a corresponding physical size of a laser beam spot used to write the image on a Xerographic photoreceptor. The laser driver may be modified to drive a light emitting element with a boost current profile that includes an overshoot above a steady state current at a rising edge. The overshoot results in a light intensity time profile that has an increased area for a subpixel.12-17-2009
20120183005DRIVING CIRCUIT FOR ANALOG-MODULATED DIODE-LASER - A diode-laser is driven by a modulated voltage through a voltage-to-current converter. The modulated voltage has a fixed level determined by an applied fixed bias voltage and a variable level determined by a modulation voltage signal varying between minimum and maximum values. The fixed voltage level corresponds to a threshold level above which the diode-laser would provide laser-output. The modulation voltage signal is monitored and compared with a predetermined set value. If the monitored voltage signal falls below the set value, the modulated voltage is disconnected from the voltage-to-current converter and the output of the diode-laser falls to zero.07-19-2012
20110170567LASER BANDWIDTH INTERLOCK CAPABLE OF SINGLE PULSE DETECTION AND REJECTION - A pulse of laser light is switched out of a pulse train and spatially dispersed into its constituent wavelengths. The pulse is collimated to a suitable size and then diffracted by high groove density multilayer dielectric gratings. This imparts a different angle to each individual wavelength so that, when brought to the far field with a lens, the colors have spread out in a linear arrangement. The distance between wavelengths (resolution) can be tailored for the specific laser and application by altering the number of times the beam strikes the diffraction gratings, the groove density of the gratings and the focal length of the lens. End portions of the linear arrangement are each directed to a respective detector, which converts the signal to a 1 if the level meets a set-point, and a 0 if the level does not. If both detectors produces a 1, then the pulse train is allowed to propagate into an optical system.07-14-2011
20090262769LASER DRIVE CIRCUIT AND USE - A laser drive circuit and use of digital-to-analog converters is provided, each with a current input and a current output to set current values of partial currents switchable by means of digital channel signals to provide a laser current pulse at least on the basis of a sum of partial currents, wherein at least one current output of one of the digital-to-analog converters is connected to at least one current input of an additional digital-to-analog converter via an analog switch.10-22-2009
20090274185Laser Drive Amplifier - A laser drive amplifier apparatus includes a device (e.g., Class A amplifier or digital-to-analog converter) driving a laser diode. A programmable switching power supply provides a power supply voltage for the device driving the laser diode. One or more voltages on the device are measured, and the power supply voltage is changed in response thereto. The power supply voltage may be updated for each video line, video frame, or zone in a video display.11-05-2009
20090290609LASER DRIVING APPARATUS - Laser driving apparatus in which a temperature is controlled such that an optical output is maximum, even when a laser device using an optical wavelength conversion element is used in a backlight source of a liquid crystal display that adjusts light dynamically. Current detection section 11-26-2009
20080212628Auto-power control circuit to maintain extinction ratio of optical output from laser diode - The present invention provides an auto-power control (APC) circuit and a method to stabilize the extinction ratio of an optical output from a laser diode (LD) in an optical transmitter. The APC circuit according to the invention includes two feedback loops for the modulation I09-04-2008
20080212627Laser control system, optical scanning device, and image forming apparatus - A control system for a laser source driven by a direct current drive voltage includes a system control board, a laser driver, and a power stabilizing circuit. The system control board is configured to output a control signal based on input data. The laser driver is coupled to the laser source and to the system control board. The laser driver is configured to drive the laser source with the drive voltage to generate a laser beam modulated according to the control signal. The power stabilizing circuit is configured to regulate the drive voltage to a given constant level. The power stabilizing circuit includes a first circuit and a second circuit. The first circuit is configured to boost the drive voltage to a level exceeding the given constant level. The second circuit is configured to limit the boosted drive voltage to the given constant level.09-04-2008
20120294324SEMICONDUCTOR LASER DRIVE CIRCUIT AND SEMICONDUCTOR LASER APPARATUS - A semiconductor laser drive circuit controlling a semiconductor laser diode connected to an output terminal by providing a drive electric current to the semiconductor laser diode includes: a constant electric current source configured to provide an electric current to the output terminal, the constant electric current source being connected to a first electric power terminal and the output terminal; a current sinking circuit connected to the output terminal and a second electric power terminal; a current sourcing circuit configured to provide a predetermined electric current to the output terminal or the current sinking circuit, the current sourcing circuit being connected to the first electric power terminal and the output terminal; and a terminating resistor having a resistance component equal to that of the semiconductor laser diode, the terminating resistor being connected to the circuit sinking circuit and the current sourcing circuit.11-22-2012
20080279240SEMICONDUCTOR LASER DRIVING UNIT AND IMAGE FORMING APPARATUS HAVING THE SAME - A semiconductor laser driving unit is disclosed that includes a first part generating a bias current; a second part generating a first current for causing the semiconductor laser to emit light, and outputting the first current to the semiconductor laser in accordance with an input control signal; a third part performing initialization to detect a light emission characteristic of the semiconductor laser, and causing the second part to generate a second current of a value obtained from the detected light emission characteristic; and a fourth part causing the second part to generate the first current in which a set offset current is added to the second current. The first part detects the amount of light emission of the semiconductor laser, and generates and outputs the bias current so that the amount of light emission produced by the sum of the bias current and the first current is a predetermined value.11-13-2008
20080304527Controlling a bias current for an optical source - In one embodiment, the present invention includes an apparatus having a current mirror with a current source coupled to a first terminal and an output current to flow from an output terminal, a laser coupled to the output terminal to be biased by the output current, and a comparator to compare a voltage of the first terminal to the voltage of the output terminal and gate the current mirror based on the comparison. Other embodiments are described and claimed.12-11-2008
20090161710Laser array circuit - A laser array circuit decreases the size of a circuit pattern. A laser-diode (LD) driving switching element with a low on resistance is used in common with and switches conduction and non-conduction of a large current to each of a plurality of charge capacitors and charge switching elements that accumulate charge in the charge capacitors in respective drive circuits. An LD array and the LD driving switching element are closely located on a light-emitting board. By laying out the LD array and charge capacitors considering only the positional relationship therebetween, the size of a circuit pattern including LDs and the charge capacitors can be decreased.06-25-2009
20080317079DRIVE CIRCUIT AND DRIVE METHOD FOR SEMICONDUCTOR LIGHT SOURCE - a circuit for driving a semiconductor laser including a semiconductor integrated circuit, which controls the drive of the semiconductor laser, and is connected to one end of the semiconductor laser. Moreover, the driving circuit incorporates a first power source +Vcc that supplies by way of the semiconductor integrated circuit a drive voltage to one end of the semiconductor laser and a second power source −Vcc, which is connected to the other end of the semiconductor laser and supplies a drive voltage to the other end. Furthermore, the drive circuit incorporates a voltage clamp circuit, connected to a connection terminal connecting the semiconductor laser and the semiconductor integrated circuit, for adjusting the electric potential of the connection terminal.12-25-2008
20090141762SEMICONDUCTOR DEVICE AND SEMICONDUCTOR LASER DRIVING DEVICE - In a semiconductor device, a switching current generator circuit generates and outputs a switching current such that a voltage input to a switching current setting terminal is equal to a voltage input to a switching current control terminal, and a bias current generator circuit generates and outputs a bias current such that a voltage input to a bias current setting terminal equals a voltage input to a bias current control terminal. A memory circuit inputs a voltage according to an amount of light emitted by a semiconductor laser, and generates a voltage to make the input voltage equal to a predetermined first reference voltage corresponding to a predetermined amount of light. An APC output terminal outputs the voltage output by the memory circuit to an external device. A current adding circuit combines the switching current and the bias current to generate a drive current to drive the semiconductor device.06-04-2009
20090141760DRIVE CONTROL APPARATUS AND DRIVE CONTROL METHOD OF SEMICONDUCTOR LASER - According to one embodiment, a drive control apparatus of a semiconductor laser includes a driving circuit which drives the semiconductor laser by applying pulses transiting from bias current to peak current to the semiconductor laser as laser driving current that causes relaxation oscillation of emission light intensity of the semiconductor laser, and a control circuit which controls the bias current such that the bias current has a predetermined ratio limiting fluctuation of a leading peak value of the relaxation oscillation occurring for each application of pulses relative to threshold current of the semiconductor laser. The control circuit changes the bias current to maintain the predetermined ratio relative to fluctuation of the threshold current.06-04-2009
20130121356DRIVER CIRCUIT AND OPTICAL TRANSMITTER - An apparatus includes a first input transistor to include a base receiving a drive signal for an object to be driven, a first current source connected to an emitter side of the first input transistor and configured to control a modulation amplitude of a signal flowing to a collector of the first input transistor, a second current source connected to a collector side of the first input transistor and configured to control a biased current of a signal flowing to the collector, a first inductor configured to dispose between the collector and the second current source, and an output element connected between the second current source and the first inductor and configured to output, to the object, a current signal of which the modulation amplitude is controlled by the first current source and the biased current is controlled by the second current source.05-16-2013
20130121357LASER DIODE WITH WAVE-SHAPE CONTROL - An optical disk drive system associated with a laser diode is described. The optical disk drive system comprises a current generator for receiving input signals; a current switch coupled to receive timing signals; a current driver coupled to receive output signals from the current switch and the current generator, the current driver further comprising a driver with wave shape control selected from the group consisting of a laser diode read driver and a laser diode write driver, wherein the driver with shape control is operative for transmitting at least one output signal that is a scaled version of at least one of the output signals received from the current generator, wherein the current driver is operative for transmitting at least one output signal driving the laser diode.05-16-2013
20110228802SEMICONDUCTOR LASER DRIVING UNIT, OPTICAL SCANNER HAVING SEMICONDUCTOR LASER DRIVING UNIT, AND IMAGE FORMING APPARATUS - Disclosed is a semiconductor laser driving unit that outputs a driving current for driving a semiconductor laser. A value of a correction current is set in such a manner as to determine a rising characteristic and/or a falling characteristic of an output of the driving current in accordance with a value of the driving current.09-22-2011
20090141759METHOD FOR DERIVING PRECISE CONTROL OVER LASER POWER OF AN OPTICAL PICKUP UNIT, AND ASSOCIATED AUTOMATIC POWER CALIBRATION CIRCUIT - A method for deriving precise control over laser power of an optical pickup unit (OPU) includes: providing an analog-to-digital converter (ADC) within an automatic power calibration (APC) circuit to derive a path gain and/or a path offset from the APC circuit; and selectively performing compensation according to the gain and/or the path offset, in order to maintain precision of a relationship between the laser power and a target command utilized for controlling the laser power. An associated APC circuit comprising an ADC and at least one compensation module is further provided. The ADC is utilized for deriving a path gain and/or a path offset from the APC circuit. The compensation module is utilized for selectively performing compensation according to the path gain and/or the path offset, in order to control the laser power by a target command.06-04-2009
20090245309Dispersion Compensating Varactor Circuit - Improved dispersion compensating circuits for optical transmission systems are disclosed. According to the improved method, there is provided a compensation circuit comprising a varactor diode network. The network is preferably inserted between a source of laser modulating signal and the laser. A low-pass filter or all pass filter constructs the network. The network preferably includes an inductor or inductors and a combined circuit, which includes varactors. The network preferably provides an amplitude dependent delay of the modulating signal applied to the laser or to the optical receiver as post dispersion correction circuitry. In a first embodiment, a fixed capacitor is in series with a varactor and connected to a DC bias through inductor. Additional embodiments, using multiple varactors in different circuit configurations, with particular advantages for various applications identified.10-01-2009
20130215920LASER ARRANGEMENT AND SYSTEM, AND A MEDICAL LASER TREATMENT SYSTEM THEREOF - A method for providing a laser beam and a laser arrangement that includes an elongated tube; an elongated discharge region within the elongated tube including a discharge medium to be excited to induce laser radiation; two DC discharge electrodes disposed at opposite ends of the elongated discharge region; two RF electrodes disposed at opposite elongated sides of the elongated discharge region; and/or a laser resonator having two opposite mirrors disposed at opposite ends of the elongated tube, the laser resonator is unstable in at least one lateral axis. The method includes applying a DC discharge between the DC electrodes, and applying a RF discharge transverse to the DC discharge between the RF electrodes. The DC and RF discharges may be provided by the DC and/or RF voltage suppliers provided according to embodiments of the present invention.08-22-2013
20100238961SYSTEM AND METHOD TO REGULATE HIGH CURRENT RADIATION SOURCES - Disclosed is a high current radiation system. The system includes a high current radiation source to generate radiation and an analog circuit to generate, based, at least in part, on an input signal representative of the present current level delivered to the high current radiation source and a user-controlled input representative of a desired current level, an output signal to control a current level to be delivered to the high current radiation source. The system further includes a current driver to control the current delivered to the high current radiation source based, at least in part, on the output signal of the analog circuit.09-23-2010
20100220756LASER APPARATUS AND EXTREME ULTRAVIOLET LIGHT SOURCE APPARATUS - A laser apparatus comprises an amplifier including at least one of a MOPA and a MOPO each of which amplifies a single-longitudinal or multiple-longitudinal mode laser light, an amplifiable agent of the amplifier being a molecular gas, a master oscillator constructed from a semiconductor laser being able to oscillate a single-longitudinal or multiple-longitudinal mode laser light of which wavelength is within one or more amplification lines of the amplifier; and a controller executing a wave shape control adjusting a pulse shape and/or a pulse output timing of a single-longitudinal or multiple-longitudinal mode laser light outputted from the master oscillator.09-02-2010
20090219964 LASER DIODE DRIVER - An apparatus for driving a laser diode (09-03-2009
20090016394LASER DIODE DRIVING DEVICE AND OPTICAL SCANNING DEVICE - A laser diode driving device capable of obtaining a stable pulse emission state even when variation in the current-light amount characteristic of a laser diode thereof is caused by environmental changes. A photodiode detects the amount of light emitted from the laser diode. A laser controller determines the amount of light to be emitted from the laser diode. Further, the laser controller controls the laser diode to emit light in the determined light amount. A bias current value-determining section determines a bias current value based on results of light emission performed by the laser diode in three or more kinds of light amounts determined by the laser controller.01-15-2009
20090110015Current Driver And Power Control For Electrophotographic Devices - A laser driver comprises a plurality of current sources, including at least one bias current source and at least two drive current sources. To control the laser driver, a set of operating states is defined where each operating state corresponds to a desired laser output power level and a ratio is defined that establishes a relationship between a first desired laser output and a second desired laser output. A calibration operation samples laser output power of the laser source for less than all of the operating states, computes adjustments to the current levels of the current sources based at least in part upon the ratio such that sampled laser power levels converge towards their corresponding desired laser output level. The current sources are adjusted to their corresponding computed current levels.04-30-2009
20100322273LIGHT EMISSION DEVICE, LIGHT EMISSION DEVICE DRIVING METHOD, AND PROJECTOR - A light emission device includes: a first clad layer; an active layer disposed above the first clad layer; a second clad layer disposed above the active layer; a first electrode electrically connected with the first clad layer; and second electrodes electrically connected with the second clad layer, wherein at least a part of the active layer forms a plurality of gain areas, the plural second electrodes are provided in correspondence with the plural gain areas, the plural gain areas extend from a first side of the active layer to a second side of the active layer opposed to the first side while inclined to a vertical line of the first side in the plan view, at least a first gain area and a second gain area included in the plural gain areas form a set of gain areas, a plurality of the sets of the gain areas are provided, the first gain area and the second gain area included in each set of the gain areas are disposed in this order in a second direction perpendicular to a first direction extending from the first side to the second side in the plan view, the second electrodes disposed above the plural first gain areas are electrically connected with one another by a first common electrode, and the second electrode disposed above the plural second gain areas are electrically connected with one another by a second common electrode.12-23-2010
20100322274LIGHT TRANSMITTER AND AUTOMATIC POWER CONTROL CIRCUIT THEREOF - A light transmitter and an auto-control circuit thereof are provided. The circuit includes a driving module and a feedback module. The driving module is coupled to the feedback module and a load. The driving module provides a driving current for driving the load. The feedback module provides a bias signal to the driving module according to the change of the temperature, for adjusting the driving current and stabilizing an output power.12-23-2010
20110019706SHUNT DRIVER CIRCUIT FOR SEMICONDUCTOR LASER DIODE - A driver circuit for the laser diode is disclosed. The driver circuit has the shunt configuration with a switching transistor connected in parallel to the laser diode to shunt the current flowing in the laser diode. In the present invention, the bias for the switching transistor is varied as the operating temperature of the laser diode. In addition, the gate bias for the switching transistor is compensated for the temperature dependence of the switching transistor.01-27-2011
20100027574OPTICAL INFORMATION RECORDING DEVICE, OPTICAL PICKUP, AND METHOD FOR EMITTING LASER LIGHT - An optical information recording device includes a semiconductor laser for emitting laser light, a light irradiation section for collecting the laser light and irradiating an optical information recording medium with the laser light, and a laser controller for supplying the semiconductor laser with a laser drive current wave in pulse form. The laser drive current wave has an oscillation current value that causes a relaxation oscillation of the semiconductor laser.02-04-2010
20090323744CIRCUIT AND METHOD FOR DRIVING LIGHT-EMITTING ELEMENT AND OPTICAL TRANSMITTER - A circuit for driving a light-emitting element such as a laser diode LD has a boost circuit for boosting an input voltage to supply it to the light-emitting element, a photoreceptor such as a photodiode PD for monitoring light from the light-emitting element; and a boost control circuit for controlling a boost voltage of the boost circuit based on a monitored amount of the photoreceptor. In the method for driving a light-emitting element by boosting an input voltage to supply the voltage to the light-emitting element, light from the light-emitting element is monitored and its monitored amount is used as a basis to control a boost voltage to the light-emitting element. A control circuit may be provided to control a driving current that passes through the light-emitting element based on the monitored amount of the photoreceptor.12-31-2009
20100128748MONITORING METHOD AND DEVICE FOR MONITORING A FORWARD VOLTAGE OF A LASER DIODE IN A LASER DIODE DRIVER INTEGRATED CIRCUIT (IC) - A laser diode driver IC of a transmitter or transceiver is provided with circuitry for monitoring the forward voltage of the laser diode or laser diodes of the transmitter or transceiver to enable the health of the laser diode or diodes to be assessed in real-time.05-27-2010
20120201260Symmetrical, Direct Coupled Laser Drivers - Symmetrical, direct coupled laser drivers for high frequency applications. The laser drivers are in integrated circuit form and use a minimum of relatively small (low valued) external components for driving a laser diode coupled to the laser driver through transmission lines. An optional amplifier may be used to fix the voltage at an internal node at data frequency spectrum to improve circuit performance. Feedback to a bias input may also be used to fix the voltage at the internal node. Programmability and a burst mode capability may be included.08-09-2012
20110249693METHOD OF DRIVING SEMICONDUCTOR LASER - The present invention provides a method of driving a semiconductor laser, where the method can control changes in the internal temperature of a device as well as control optical output using a driving current. A method of driving a semiconductor laser includes steps of: preliminary driving the semiconductor laser by preliminary activating at a current value larger than a threshold value; de-activating the semiconductor laser, after the step of preliminary driving; and starting a formation of a latent image on a photosensitive drum based on a latent image formation signal, after the step of de-activating.10-13-2011
20100278202SEMICONDUCTOR LASER DRIVING DEVICE AND IMAGE FORMING APPARATUS HAVING THE SAME - A semiconductor laser driving device and an image forming apparatus are disclosed that are capable of accurately detecting the deterioration of the semiconductor laser with a smaller circuit size and regardless of the variation of the characteristics of the semiconductor laser and the use conditions of the semiconductor laser by adding a minimum circuit are disclosed. In the semiconductor laser driving device, the output voltage generated by an operational amplifier circuit by amplifying a voltage difference between a monitoring voltage (Vm) and a predetermined reference voltage (Vref) is transmitted to a bias current generating circuit unit as a bias current setting voltage (Vbi) through a sample/hold circuit having a switch (SW1) and a sample/hold capacitor (Csh). When the bias current setting voltage (Vbi) is greater than a predetermined voltage, a deterioration detecting circuit transmits a deterioration detecting signal indicating that the deterioration of the semiconductor laser is detected.11-04-2010
20100260220SEMICONDUCTOR LASER DEVICE AND CIRCUIT FOR AND METHOD OF DRIVING SAME - A directly driven laser includes multiple contacts, with at least one of the contacts for injecting current into the laser such that the laser reaches at least a lasing threshold and at least one of the contacts for providing a data signal to the laser. In some embodiments a differential data signal is effectively provided to a front and a rear section of the laser, while lasing threshold current is provided to a central portion of the laser.10-14-2010
20090141761LIGHT SOURCE DEVICE, LIGHTING DEVICE, MONITORING DEVICE, AND IMAGE DISPLAY APPARATUS - A light source device includes a plurality of first laser emission units and a plurality of second laser emission units for emitting light. The plurality of first laser emission units and the plurality of second laser emission units are disposed on a flat surface. The first laser emission units and the second laser emission units are composed so that a drive for light emission is sequentially switched. Each of the second laser emission units is disposed between the adjoining first laser emission units.06-04-2009
20090028200LASER DIODE DRIVE CIRCUIT, ELECTRONIC CIRCUIT, METHOD FOR CONTROLLING LASER DIODE DRIVE CIRCUIT, AND METHOD FOR CONTROLLING DUTY - A laser diode drive circuit includes: a duty control amplifier (01-29-2009
20080253417Error control for high-power laser system employing diffractive optical element beam combiner with tilt error control - A high-power laser system includes a laser master oscillator, a plurality of fiber laser amplifiers producing intermediate output beamlets, a diffractive optical element for combining the intermediate beamlets into a combined output beam, and one or more error controllers for minimizing errors related to beam combination that may degrade the quality of the combined output beam. A piston error controller uses phase modulation to tag each non-reference intermediate beamlet with a unique dither signal harmonically unrelated to those used for the other beamlets. For each intermediate beamlet, the associated piston error is recovered using a synchronous detector, and an error control signal proportional to the piston error is supplied to a phase modulator to control the piston error for that beamlet. A tilt error controller uses amplitude modulation based on Hadamard code words to tag each non-reference intermediate beamlet with a unique code sequence orthogonal to those used for the other beamlets. For each intermediate beamlet, the associated tilt error is recovered using a Hadamard decoder, and an error control signal proportional to the tilt error is supplied to a beam steerer to control the tilt error for that beamlet.10-16-2008
20110116524SEMICONDUCTOR LASER DEVICE AND METHOD FOR CONTROLLING SEMICONDUCTOR LASER - A semiconductor laser device includes: a semiconductor laser having a reflector region, a gain region for laser oscillation and a plurality of refraction index controllers, the reflector region having a plurality of segments in which a diffraction region and a space region are coupled to each other, the plurality of segments being separated into a plurality of segment groups having a same optical length, the plurality of refractive index controllers being provided according to each segment group and controlling an equivalent refraction index of each segment group; a wavelength controller controlling an oscillation wavelength of the semiconductor laser by controlling the plurality of the refraction index controllers as at least one of control parameters; and a dither controller inputting a dither signal into only one of the segment groups having the most segments from one of the refractive index controllers according to the segment group.05-19-2011
20100329293Methods and Apparatus for Efficient, Low-noise, Precision Current Control - Improved current controllers of the present invention provide efficient, low noise, precision current control for devices having such operational requirements. The current controllers are characterized by a PWM regulator operably connected to a linear regulator. The PWM regulator regulates a voltage drop across the linear regulator, wherein the voltage provided to the linear regulator is greater than the output voltage of the linear regulator by a controlled operating margin. The PWM provides efficient power conversion and minimizes waste power dissipation in the linear regulator. The linear regulator, in turn, provides low noise, precision current drive to the connected load.12-30-2010
20100260219Laser drive - Disclosed herein is a laser driver including a light emission controlling section configured to stop generation of a control voltage by a control voltage generating section, causing a given voltage corresponding to a magnitude of a reference current to be outputted to an input node of a first emitter follower to operate the first emitter follower for a first time period from start of a light emission time period, release stop of the generation of the control voltage by the control voltage generating section, causing the control voltage to be outputted to the input node of the first emitter follower to operate the first emitter follower until end of the light emission time period of the laser, and operate a second emitter follower to discharge electric charges accumulated in the laser for a second time period after the end of the light emission time period of the laser.10-14-2010
20080219306Laser Power Algorithm for Low Power Applications - A system and method to minimize the power consumed by a light source. The power of a light source in controlled in response to a determination of the quality of the received data in order to optimize a reduction in power consumption. If the quality of the received data is sufficient, then the laser power can be reduced in order to save power.09-11-2008
20100166030EXPOSURE APPARATUS, LIGHT SOURCE APPARATUS AND METHOD OF MANUFACTURING DEVICE - An apparatus exposes a substrate via a pattern of a reticle using pulsed light generated by a light source, and includes a controller configured to control the light source so that the oscillation frequency of the light source changes periodically while the apparatus exposes the substrate. The oscillation frequency is the number of times of emission of the light source per unit time.07-01-2010
20110261846VERTICAL CAVITY SURFACE EMITTING LASER APPARATUS - A surface emitting laser apparatus includes an arithmetic processing unit including an I/O unit for externally inputting an instruction and a core unit that performs an operation based on the instruction and outputs a differential voltage signal modulated with a predetermined amplitude according to a result of the operation, capacitors respectively arranged on output paths of the differential voltage signal, and a surface emitting laser device that is directly connected to the arithmetic processing unit via the capacitors. An I/O voltage and a core voltage are externally supplied to the I/O unit and the core unit, respectively. The arithmetic processing unit generates a driving voltage signal by superimposing the differential voltage signal with the core voltage commonly supplied as a bias voltage without stepping up or down the core voltage and without amplifying the differential voltage signal and supplies the driving voltage signal to the surface emitting laser device.10-27-2011
20110051763Determining and setting the frequency modulation index of a laser in a CPT frequency standard - A technique for determining the modulation index of a frequency-modulated laser source from the absorption spectrum that is produced when light from the laser passes through an alkali metal vapor cell. The absorption spectrum contains a primary minimum and a number of satellite minima and the modulation index is determined using ratios of the minima. The technique is used to calibrate the laser source of a CPT frequency standard so that it operates at a desired modulation index. Ways are disclosed of using the technique to calibrate the CPT frequency standard either manually or automatically. The calibration may be done when the CPT frequency standard is built, when the frequency standard is initialized, or during normal operation of the CPT frequency standard.03-03-2011
20110051762Pulse Mode Modulation In Frequency Converted Laser Sources - Methods of operating a frequency-converted laser source are disclosed. According to particular disclosed embodiments, a laser diode is driven in a pulsed mode to define pixel intensity values corresponding to desired gray scale values of image pixels in an image plane of the laser source. The pixel intensity values are a function of a laser control signal comprising a discontinuous pulse component, a relatively constant intensity component I, and a continuously variable intensity component I*. The pulse width w of the discontinuous pulse component is selected from a set of discrete available pulse widths according to a desired pixel gray scale value. A low-end pulse width w of the set of available pulse widths is established for a range of low-end pixel gray scale values and progressively larger pulse widths w are established for ranges of progressively higher pixel gray scale values. The relatively constant intensity component I makes a relatively insignificant contribution to pixel intensity at the low-end pulse width w for the range of low-end pixel gray scale values and assumes a non-zero value for enhanced conversion efficiency at the progressively larger pulse widths w established for the higher pixel gray scale values. The continuously variable intensity component I* varies according to the desired gray scale value of the selected pixel and the contributions of the relatively constant intensity component I and the pulse width w to pixel intensity.03-03-2011
20110051761OPERATING METHOD OF EXCIMER LASER SYSTEM - An operating method of an excimer laser system includes following steps. First, a halogen gas with an injection volume is injected into a chamber until a pressure of the chamber is a total pressure. The halogen gas in the chamber has a halogen pressure. Thereafter, a driving voltage is provided between two electrodes in the chamber so as to start the excimer laser system. The halogen pressure and a full width half maximum of a laser light generated by the excimer laser system have negative relation, and the halogen pressure and the driving voltage have positive relation.03-03-2011
20110164636LD-DRIVER IMPROVING FALLING EDGE OF DRIVING SIGNAL - An LD driver is disclosed, which improves the rising and falling times of the driving current for the LD. The LD driver includes an inverting amplifier, an emitter follower connected in down stream of the inverting amplifier, a driving transistor driven by the emitter follower, and a current-mirror circuit connected in series to the inverting amplifier. The mirror current generated from the current flowing in the inverting amplifier is provided to the output of the emitter follower served for discharging the input capacitance of the driving transistor.07-07-2011
20120307852IMPEDANCE-MATCHING TRANSFORMERS FOR RF DRIVEN CO2 GAS DISCHARGE LASERS12-06-2012
20120147914Optical module - There are provided an optical module including a semiconductor laser including a P-side electrode and an N-side electrode, and a semiconductor laser driver circuit that drives the semiconductor laser so as to output an optical signal from the semiconductor laser according to a pattern of a differentially transmitted digital electric signal, and the semiconductor laser driver circuit includes a positive-side terminal and a negative-side terminal for differentially transmitted non-inverted data, and a positive-side terminal and a negative-side terminal for differentially transmitted inverted data, and one terminal for the non-inverted data is electrically connected to one electrode of the semiconductor laser, and the other terminal for the non-inverted data, one terminal for the inverted data and the other terminal for the inverted data each are connected to the other electrode of the semiconductor laser.06-14-2012
20110158272HIGH POWER MULTI-WAVELENGTH LASER SOURCE - An optical assembly comprises a combination of a number of single spatial mode semiconductor optical gain elements, a number of microlenses, and a wavelength-selective planar lightwave circuit (PLC) that routes light of different wavelengths from a different inputs to a single output. The microlens elements couple light from the semiconductor optical gain elements into the PLC waveguides. The positions of the microlens elements can be adjusted using lithographically fabricated micromechanical holders that are an integral part of the carrier, and are free to move initially. Micromechanical techniques are used to adjust the position of the lenses and holder, and then fix the holder it into place permanently after optimization of the optical coupling. In operation, the gain elements are activated simultaneously, and each gain element causes one wavelength of light to lase within the structure. All output wavelengths of light exit from a single output port of the PLC and are in a single spatial mode.06-30-2011
20110317729CURRENT DRIVING DEVICE - A current driving device comprises; a three-terminal regulator configuration circuit operative as a three-terminal regulator which drops a voltage of a first electric power supply to a predetermined target output voltage in a state where a main terminal and a control terminal of a power transistor are connected to a main terminal connection terminal and a control terminal connection terminal, respectively; a voltage setting circuit which sets a control voltage corresponding to a target output voltage which is applied from the three-terminal regulator configuration circuit to the control terminal of the power transistor; and a voltage restricting circuit which is connected to the control terminal connection terminal and controls the control voltage applied to the control terminal of the power transistor so that the output voltage of the three-terminal regulator configuration circuit becomes a predetermined voltage or less, upon being supplied with the electric power from the first electric power supply.12-29-2011
20120008656DEVICE FOR JUDGING STATE OF SEMICONDUCTOR LASER AND METHOD FOR JUDGING STATE OF SEMICONDUCTOR LASER - A device includes: a providing unit that provides a driving electric current to a semiconductor laser, the electric current being superimposed a first alternating current signal having a first frequency at a low side of an operational range of the semiconductor laser and a second alternating current signal having a second frequency at a high side of the operational range; a first filter that extracts a first component corresponding to the first frequency from a voltage to be applied to the semiconductor laser; a second filter that extracts a second component corresponding to the second frequency from the voltage to be applied to the semiconductor laser; and a judge circuit that judges a state of the semiconductor laser based on a first differential resistance obtained from the result of the extracting by the first filter and a second differential resistance obtained from the result of the extracting by the second filter.01-12-2012
20120014401SEMICONDUCTOR LASER DRIVER AND IMAGE FORMING APPARATUS INCORPORATING SAME - A semiconductor laser driver to execute automatic power control (APC) for multiple semiconductor lasers based on a common APC output from an image controller. The semiconductor laser driver includes a drive circuit to generate an individual APC signal to execute APC for each semiconductor laser based on the common APC signal.01-19-2012
20120027037SEMICONDUCTOR LASER DRIVE DEVICE AND IMAGE FORMING APPARATUS INCORPORATING SAME - A semiconductor laser drive device includes a semiconductor-laser drive element to generate a drive current according to an input control signal to supply the drive current to a semiconductor laser, a control circuit to control the drive current by controlling the semiconductor-laser drive element, and a drive current detection circuit to detect a current value of the drive current supplied to the semiconductor laser and generate a digital control signal representing the detected digital value of the drive current to output.02-02-2012
20090135868Optical transmitter able to resume APC operation automatically - An optical transmitter is disclosed that provides a function to resume the APC operation automatically when the failure of the APC operation is due to the thermal runaway of the device in the APC loop. The controller included in the transmitter always monitors the bias current supplied to the LD, and the optical output from the LD. When the bias current exceeds a threshold, the controller decides whether the abnormal is due to the temporary thermal runaway or the fatal failure of the device within the APC loop, and begins to sense the ambient temperature of the LD for appropriate resuming after the thermal runaway is cleared.05-28-2009
20110103417Systems, Methods, and Circuits for Driving Large Off-Chip Loads - A method and system to drive large off-chip loads, such as, for example, laser diodes, wherein the system includes an integrated circuit coupled to an external differential diode load. Alternatively, the external diode load may be driven single-ended. The integrated circuit includes a data buffer device and a clock buffer device. The integrated circuit also includes a multiplexer device coupled to the clock buffer device configured to multiplex a data input signal and a clock input signal received at respective inputs of the integrated circuit. If the external diode is single-ended, the data input signal is transmitted to the data buffer device, which is then used solely to drive the diode load. If the diode load is differential, the data buffer device receives the data input signal. At the same time, the multiplexer device receives both the data input signal and the clock input signal and selects the data signal to drive the clock buffer device. For a diode load being driven differentially, the outputs of the two buffer devices are merged together externally through the use of a power-combining network, which includes external or off-chip transmission lines, which carry a respective output signal for the data buffer device and the clock buffer device.05-05-2011
20100246621LIGHT SOURCE CONTROL APPARATUS AND LIGHT SOURCE APPARATUS - A light source control apparatus includes a laser having a wavelength that varies depending on temperature; a wavelength monitor that monitors the wavelength of light output from the laser; a temperature controller that controls the temperature of the laser based on an output of the wavelength monitor; a temperature monitor that monitors the temperature of the laser; and a control manager that stops control by the temperature controller if a variation amount per unit time of the temperature monitored by the temperature monitor exceeds a threshold value.09-30-2010
20120213237 DRIVER FOR SUPPLYING MODULATED CURRENT TO A LASER - A driver device for a laser includes a control device configured to generate a control current, an NPN differential amplifier connected to the control device and configured to superimpose a modulation current onto the control current to generate a combined current, and a laser activation switch coupled to the output of the NPN differential amplifier, the laser activation switch operating the laser utilizing the combined current. Also described herein is a communication system including a driver device.08-23-2012
20120134379MULTI-BEAM LASER POWER CONTROL CIRCUIT AND IMAGE FORMING APPARATUS USING THE SAME - A disclosed multi-beam laser power control circuit includes a light receiving element receiving power output from semiconductor lasers to control output power of a semiconductor laser array having plural semiconductor lasers, automatic power control circuits (APC circuits) controlling emission power output from semiconductor lasers based on received corresponding automatic power control execution signals so as to be set to predetermined emission power based on output from the light receiving element, and APC execution signal input terminals inputting the corresponding automatic power control execution signals, wherein, when plural APC execution signals input to the corresponding APC execution signal input terminals are overlapped, the automatic power control circuits (APC circuits) to be preferentially operated is determined based on input timings of the APC execution signals and operated.05-31-2012
20090059981DRIVE CIRCUIT FOR SEMICONDUCTOR LIGHT EMITTING ELEMENT, AND LIGHT SOURCE DEVICE, LIGHTING DEVICE, MONITOR DEVICE, AND IMAGE DISPLAY DEVICE USING THE DRIVE CIRCUIT - A drive circuit for driving a semiconductor light emitting element includes a board, a first pattern formed in a first layer of the board so as to be electrically connected to an anode of the semiconductor light emitting element, and a second pattern formed in a second layer of the board so as to be electrically connected to a cathode of the semiconductor light emitting element, and the first pattern and the second pattern are formed so as to overlap with each other when viewed in a direction along a normal line of the board.03-05-2009
20120170603PROTECTION DEVICE FOR SOLID STATE LASER - Embodiments provide systems, devices, and methods for controlling a laser. The system includes a controller to control a laser, a ramp generator to ramp down laser power, the ramp generator electrically coupled with the controller and coupleable with the laser, and a hardware protection system electrically coupled with the ramp generator, wherein the ramp generator monitors signals sent from the controller and the hardware protection system to the ramp generator to detect signal failure and ramps down the laser power upon signal failure detection. The method includes sending a control status signal from a controller for a laser to a ramp generator, monitoring the control status signal for missing pulses, sending a hardware interlock status signal from a hardware protection system to the ramp generator, monitoring the hardware interlock status signal for signal failure, and ramping down laser power upon detection of missing pulses or signal failure.07-05-2012
20090129416SEMICONDUCTOR LASER DRIVE CONTROL APPARATUS - A drive signal for driving a semiconductor laser is generated on the basis of an image signal inputted in synchronism with a pixel clock. A bias signal to the semiconductor laser is generated at a timing earlier than the drive signal by a predetermined time. The bias signal is disabled in synchronism with the leading edge of the drive signal.05-21-2009
20100272140High speed light emitting semiconductor methods and devices - A method for producing a high frequency optical signal component representative of a high frequency electrical input signal component, includes the following steps: providing a semiconductor transistor structure that includes a base region of a first semiconductor type between semiconductor emitter and collector regions of a second semiconductor type; providing, in the base region, at least one region exhibiting quantum size effects; providing emitter, base, and collector electrodes respectively coupled with the emitter, base, and collector regions; applying electrical signals, including the high frequency electrical signal component, with respect to the emitter, base, and collector electrodes to produce output spontaneous light emission from the base region, aided by the quantum size region, the output spontaneous light emission including the high frequency optical signal component representative of the high frequency electrical signal component; providing an optical cavity for the light emission in the region between the base and emitter electrodes; and scaling the lateral dimensions of the optical cavity to control the speed of light emission response to the high frequency electrical signal component.10-28-2010
20100272139DRIVING CIRCUIT FOR DRIVING LASER DIODE AND METHOD FOR CONTROLLING LASER POWERS OF LASER DIODE - The invention provides a driving circuit for driving a laser diode of a pickup head. In one embodiment, the driving circuit comprises an automatic power control (APC) module, a clamp value determination unit, and a clamp circuit. The automatic power control module generates at least one power control signal. The clamp value determination unit dynamically determines at least one clamp value corresponding to the power control signal when the pickup head accesses an optical storage medium. The clamp circuit clamps the power control signal according to the clamp value to obtain a clamped power control signal. A driving signal for driving the laser diode can then be generated according to at least the clamped power control signal.10-28-2010
20120082177LASER PROJECTOR AND METHOD OF SCANNING LASER BEAM - A laser projector for scanning a laser beam output by a multimode laser light source and displaying an image includes a laser driving unit to drive the multimode laser light source so that two-dimensional output patterns of a shape of the laser beam are different in each display frame. The laser driving unit applies to the multimode laser light source a driving waveform pattern which has the same product of an output intensity and output time of a laser light source during a display time of one dot and which includes an output intensity and output time different in each display frame.04-05-2012
20090016393Laser apparatus, laser irradiation method, and manufacturing method of semiconductor device - It is an object to provide a laser apparatus, a laser irradiating method and a manufacturing method of a semiconductor device that make laser energy more stable. To attain the object, a part of laser beam emitted from an oscillator is sampled to generate an electric signal that contains as data energy fluctuation of a laser beam. The electric signal is subjected to signal processing to calculate the frequency, amplitude, and phase of the energy fluctuation of the laser beam. The transmittance of a light amount adjusting means is controlled in order that the transmittance changes in antiphase to the phase of the energy fluctuation of the laser beam and with an amplitude capable of reducing the amplitude of laser beam emitted from the oscillator, the control being made based on the phase difference between the phase of a signal that is in synchronization with oscillation of laser beam emitted from the oscillator and the phase calculated, on the energy ratio of the sampled laser beam to laser beam emitted from the oscillator, and on the frequency and amplitude calculated. In the light amount adjusting means, energy of the laser beam oscillated from the oscillator energy is adjusted.01-15-2009
20090016392Laser Driver Automatic Power Control Circuit Using Non-Linear Impedance Circuit - A laser driver circuit includes a laser APC circuit receiving a monitor current indicative of the average optical output power of a laser diode and providing a bias adjust signal for adjusting a bias current for the laser diode. The laser APC circuit includes a first non-linear impedance circuit receiving the monitor current and generating a first voltage using a first non-linear current-to-voltage transfer function, a second non-linear impedance circuit receiving a reference current and generating a second voltage and being implemented using the same or a scaled version of the first non-linear current-to-voltage transfer function, and a comparator for comparing the first voltage with the second voltage and providing the bias adjust signal indicative of the difference between the first and second voltages. The first non-linear current-to-voltage transfer function has difference resistance portions for increasing the dynamic range of the current-to-voltage conversion.01-15-2009
20120263202LASER DIODE CONTROL DEVICE - A laser control device comprises a driver circuitry for supplying a drive current to a laser diode (LD). The device further comprises a digital storage for storing drive current values for a plurality of temperature conditions, and a central processing unit coupled to the digital storage for controlling the driver circuitry in accordance with the drive current values from said digital storage. The central processing unit is configured for multiple updating the drive current values stored in the digital storage.10-18-2012
20120269217LASER OSCILLATOR CONTROLLER - Provided is a method for controlling a laser oscillator. Such a laser oscillator is applicable to a laser processing machine and includes a plurality of oscillator modules each adapted to be driven to oscillate a laser beam. Also, such a laser oscillator is configured to collect laser beams oscillated by driven modules for output. The method includes determining the number of modules to be driven, of the plurality of oscillator modules.10-25-2012
20110255566METHOD FOR DERIVING PRECISE CONTROL OVER LASER POWER OF AN OPTICAL PICKUP UNIT, AND ASSOCIATED AUTOMATIC POWER CALIBRATION CIRCUIT - A method for deriving precise control over laser power of an optical pickup unit (OPU) includes: providing an analog-to-digital converter (ADC) within an automatic power calibration (APC) circuit to derive a path gain and/or a path offset from the APC circuit; and selectively performing compensation according to the gain and/or the path offset, in order to maintain precision of a relationship between the laser power and a target command utilized for controlling the laser power. An associated APC circuit comprising an ADC and at least one compensation module is further provided. The ADC is utilized for deriving a path gain and/or a path offset from the APC circuit. The compensation module is utilized for selectively performing compensation according to the path gain and/or the path offset, in order to control the laser power by a target command.10-20-2011
20130016747COMMAND APPARATUS IN A GAS LASER OSCILLATOR, CAPABLE OF COMMAND AT HIGH SPEED AND WITH HIGH PRECISIONAANM HONDA; MasahiroAACI Minamitsuru-gunAACO JPAAGP HONDA; Masahiro Minamitsuru-gun JPAANM IKEMOTO; HajimeAACI YamanashiAACO JPAAGP IKEMOTO; Hajime Yamanashi JP - A command apparatus (01-17-2013
20130016748TRANSIMPEDANCE AMPLIFIER, SEMICONDUCTOR DEVICE, AND OPTICAL MODULEAANM TAKEMOTO; TakashiAACI FuchuAACO JPAAGP TAKEMOTO; Takashi Fuchu JPAANM YAMASHITA; HirokiAACI HachiojiAACO JPAAGP YAMASHITA; Hiroki Hachioji JPAANM TSUJI; ShinjiAACI HidakaAACO JPAAGP TSUJI; Shinji Hidaka JP - An optical module including a transimpedance amplifier capable of realizing a high-speed and high-quality receiving operation is provided. A transimpedance amplifier includes: a pre-amplifier using a single-end current signal as an input and converting the single-end current signal to a single-end voltage signal; an automatic decision threshold control detecting a center electric potential of the single-end voltage signal serving as an output of the pre-amplifier; a post-amplifier differentiating and amplifying the single-end voltage signal of the output of the pre-amplifier; and a power circuit supplying power to the pre-amplifier. Particularly, in accordance with an input voltage signal or an output voltage signal of the pre-amplifier, the power circuit outputs a varied current that flows to a supply terminal of the pre-amplifier and a varied current having a phase opposite to that of the varied current. Thus, the power supply current change is cancelled out.01-17-2013
20130022069HIGH POWER SURFACE MOUNT TECHNOLOGY PACKAGE FOR SIDE EMITTING LASER DIODE - The present invention relates to the packaging of high power laser(s) in a surface mount technology (SMT) configuration at low-cost using wafer-scale processing. A reflective sidewall is used to redirect the output emission from edge-emitting lasers through an optical element (e.g., a diffuser, lens, etc.). A common electrical pad centered inside the package provides p-side connection to multiple laser diodes (i.e. for power scalability). Thick plating (e.g. 75 um to 125 um) with a heat and electrically conductive material, e.g. copper, on a raised bonding area of a substrate provides good heat dissipation and spreading to the substrate layer during operation. The composite CTE of the substrate layer, e.g. AlN, and the heat/electrical conductive plating, e.g. Cu, substantially matches well with the laser substrates, e.g. GaAs-based, without the requirement for an additional submount.01-24-2013
20080253418Light source device, monitor device, projector, and driving method for driving light source device - A light source device includes: a plurality of laser light sources that emit laser light; and a light source driving section that drives at least one of the laser light sources by a first driving value that is a value less than a threshold level of at least one of the laser light sources, or by a second driving value that is a value greater than a threshold level of at least one of the laser light sources, and that varies at least one of the number of laser light sources that are driven by the first driving value and the number of laser light sources that are driven by the second driving value in the laser light sources, thereby controlling the total output of laser light emitted from the laser light sources.10-16-2008
20080225916Excessive current input suppressing semiconductor laser light emitting circuit - A semiconductor laser light emitting circuit includes a semiconductor laser diode emitting a laser light by modulating a current supplied thereto, a light intensity detection circuit that detects the laser light and generates a voltage, and a voltage-current conversion circuit converting a voltage into a current supplied to the laser diode. A S/H capacitance is provided to store electric charge and output a voltage to the voltage/current conversion circuit. A first operational amplifier is provided to output a first current charging the S/H capacitance. A rapidly charging circuit is provided to charge the S/H capacitance with a second current. The rapidly charging circuit terminates charging when the voltage is equal to or more than a second reference voltage.09-18-2008
20080225915Method and Apparatus for Prevention of Laser Saturation - A method and apparatus for preventing laser current saturation (09-18-2008
20080225914SYSTEM OF METHOD FOR DYNAMIC RANGE EXTENSION - The present invention generally relates to the operation of optical network equipment such as optical amplifiers. In one aspect, a method of operating an optical amplifier is provided such that output of the optical amplifier avoids the effects of operating an optical gain medium in a non-linear (kink) region of an L-I curve. The method generally includes operating an optical gain medium in a fully off state or fully on state above the kink region with a PWM signal. In another aspect, the effects of the kink region may be compensated for by utilizing a lookup table. A sample of the optical power of an amplified optical signal may be used to select an entry in the lookup table that compensates for non-linearities in the kink region. In yet a further aspect, a lookup table may be used to control a pulse modulator to compensate for non-linearites in the kink region of the L-I curve.09-18-2008
20110261845Chirp compensation and SBS suppression using a multi-section laser - A method includes driving a multi-section laser, wherein each section is electrically isolated from an adjacent section with sufficient resistance so that current through each section is contained substantially in that section. An apparatus includes a multi-section laser, wherein each section is electrically isolated from an adjacent section with sufficient resistance so that current through each section is contained substantially in that section.10-27-2011
20090122820Method Of Driving A Laser Diode - A method of driving a block of diodes having low impedance by high power pulses. A high power signal is fed through an impedance-transforming device to a block of diodes. The block of diodes includes at least one laser diode. The impedance-transforming device is one of a group of transformer or quarter wave matching section.05-14-2009
20120250713CORRECTION CIRCUIT, DRIVING CIRCUIT, LIGHT EMITTING APPARATUS, AND METHOD OF CORRECTING ELECTRIC CURRENT PULSE WAVEFORM - A correction circuit includes: a temperature rise derivation section which derives a temperature rise amount of a first channel of a multi-channel surface-emitting laser array due to the heating by at least one or a plurality of second channels adjacent to the first channel out of all channels included in the laser array; and a first correction section which corrects a waveform of an electric current pulse which is output from an electric current source capable of independently driving the laser array for each channel, to the first channel, based on the temperature rise amount derived by the temperature rise derivation section.10-04-2012
20130114632METHOD AND SYSTEM FOR COMMUNICATING WITH A LASER POWER DRIVER - A system for controlling a plurality of laser diodes includes an optical transmitter coupled to the laser diode driver for each laser diode. An optical signal including bi-phase encoded data is provided to each laser diode driver. The optical signal includes current level and pulse duration information at which each of the diodes is to be driven. Upon receiving a trigger signal, the laser diode drivers operate the laser diodes using the current level and pulse duration information to output a laser beam.05-09-2013
20130094530SEMICONDUCTOR LASER DRIVING CIRCUIT AND SEMICONDUCTOR LASER DEVICE INCLUDING THE SAME - A semiconductor laser driving circuit supplies a drive current to a semiconductor laser diode connected to an output terminal based on an input signal inputted thereto through an input terminal, thereby controlling the semiconductor laser diode. The semiconductor laser driving circuit includes a first supply portion supplying a bias current, and a first supply signal having a frequency component whose frequency is equal to or lower than a first frequency of the input signal, and a second supply portion supplying a second supply signal having a frequency component whose frequency is higher than a second frequency of the input signal.04-18-2013
20090296764FREQUENCY-AGILE RF-POWER EXCITATION FOR DRIVING DIFFUSION-COOLED SEALED-OFF, RF-EXCITED GAS LASERS - A gas discharge laser includes a laser housing including a laser gas and an electrode-assembly for lighting a discharge in the laser gas. The electrode assembly has a first resonant frequency when the discharge is not lit and a second resonant frequency when the discharge is lit. RF power delivering circuitry of the laser includes an arrangement for determining and recording the two resonant frequencies. RF power is applied to the electrodes at the first recorded resonant frequency to facilitate lighting of the discharge, and thereafter at the second resonant frequency to light and sustain the discharge.12-03-2009
20110211606LASER DIODE DRIVE CIRCUIT AND IMAGE FORMING APPARATUS INCORPORATING SAME - A laser diode drive includes a first photo diode connection terminal to connect a first photo diode that detects light emission amounts of multiple laser diodes, multiple second photo diode connection terminals to connect multiple second photo diodes that detect light emission amounts of the respective multiple laser diodes, multiple APC controllers to control the light emission amounts of the multiple laser diodes based on monitor currents from the first photo diode or the second photo diodes, multiple switches to connect and disconnect the respective APC controllers with a monitor current path formed between the first photo diode connection terminal and the multiple APC controllers, and a detector to detect whether or not the first photo diode is connected to the first photo diode connection terminal and cause all of the switches to disconnect when the first photo diode is not connected to the first photo diode connection terminal.09-01-2011
20130156056SHUNT DRIVER CIRCUIT FOR LASER DIODE WITH PUSH PULL ARCHITECTURE - A shunt driver for driving an LD is disclosed. The shunt driver has the push-pull architecture with the high side driver and the low side driver. The high side driver is driven by a positive phase signal superposed with a signal with a phase opposite to the negative phase signal. The low side driver is driven by a negative phase signal superposed with a signal with a phase opposite to the positive phase signal. Adjusting the magnitude of the superposed signals, the driving current for the LD has the peaking in the rising and falling edges thereof.06-20-2013
20110310919Laser System Provided With a Frequency Servo - The invention relates to a laser system provided with a laser radiation device (12-22-2011
20120020382Determining the Degradation and/or Efficiency of Laser Modules - A method for monitoring a laser system including a plurality of laser modules connected in series, there being connected in parallel to each laser module a bypass arrangement for bridging the corresponding laser module, includes determining a first laser power of the laser system with a plurality of laser modules operational; activating the bypass arrangement of at least one laser module so that at least one of the plurality of laser modules is bypassed; determining a second laser power of the laser system with the at least one of the plurality of laser modules bypassed; and monitoring the laser system based on a difference between the first and second laser power.01-26-2012
20120020381OPTICAL TRANSMISSION MODULE AND CONTROLLING METHOD FOR OPTICAL TRANSMISSION MODULE - An optical transmission module includes a bias current driver circuit adapted to input bias current set in response to a temperature of a laser diode to the laser diode, a modulation current driver circuit adapted to input modulation current set in response to the temperature of the laser diode to the laser diode, and a decision circuit adapted to decide whether or not an error of optical output power of the laser diode detected by a light reception device with respect to a target value of the optical output power of the laser diode at the set bias current and the set modulation current is equal to or higher than a threshold value. The modulation current driver circuit inputs, while the error is equal to or higher than the threshold value, correction modulation current higher than the set modulation current to the laser diode.01-26-2012
20120020380MODULATION METHOD FOR DIODE-LASER PUMPED LASERS - A method of operating a digitally modulated solid state laser is disclosed. The laser is optically pumped by a current-supply driven diode-laser radiation and with output-power stabilized at a desired value by a light regulator cooperative with a power monitor and the current source is disclosed. When the laser is turned on, the current-source is enabled and the light-regulator is disabled. A current regulator allows current from the current-supply to increase until the monitored power reaches the desired value. At this point, the light regulator is enabled and the light regulator assumes control of the current-supply for maintaining the output-power at the desired level.01-26-2012
20130195133DRIVER CIRCUIT FOR LASER DIODE OUTPUTTING PRE-EMPHASIZED SIGNAL - A shunt driver for driving an LD is disclosed. The shunt driver has the push-pull arrangement with the high side driver and the low side driver. The high side driver is driven by a positive phase signal superposed with a negative phase signal with a delay and a less amplitude with respect to the positive phase signal. The low side driver is driven by a negative phase signal superposed with a positive signal with a delay and a less amplitude compared to the positive phases signal. Adjusting the magnitude of the superposed signals, the driving current for the LD has the peaking in the rising and falling edges thereof.08-01-2013

Patent applications in class For driving or controlling laser