| Institut National D'Optique Patent applications |
| Patent application number | Title | Published |
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| 20110284507 | METHOD FOR STABLIZING AN OUTPUT OF A PULSED LASER SYSTEM USING PULSE SHAPING - A method for stabilizing an output of a pulsed laser system includes a directly modulated laser diode by mitigating the effect of switching transients on the temporal shape of the outputted pulses. The method includes controlling a pulse shaping signal to define, over time, processing and conditioning periods. During the processing periods, the pulse shaping signal has an amplitude profile tailored to produce the desired temporal shape of the output. Each conditioning period either immediately precedes or follows a processing period. During a given processing period, the amplitude profile of the pulse shaping signal is tailored so that the drive current of the laser diode is lower than its maximum value during the corresponding processing period, and is of the same order of magnitude as the laser threshold current of the laser diode. In this manner, the stability of the output during the corresponding processing period is improved. | 11-24-2011 |
| 20110280265 | DRIVER 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 |
| 20110183370 | OPTICAL IMAGING FOR IDENTIFYING CELLS LABELED WITH FLUORESCENT NANOPARTICLES - An optical detection system for identifying target bacterial cells in a food sample, comprising a first fluorescent nanoparticle dye labeling specifically the target cells. A second fluorescent dye reacts non-specifically with all bacterial cells. An imaging unit optically excites the fluorescent dyes and captures images of the sample for each of two different wavelength bands emitted as a result of the excitation of the dyes. A processing unit identifies the target cells from the sample and comprises an image processing unit for processing the images of the sample. A target cell identifier identifies the target cells in the images by detecting individual units present at a same location in both of the processed images. An output unit provides data related to the identified target cells in the sample. A method is also provided. | 07-28-2011 |
| 20110170564 | FIBER LASER OSCILLATORS AND SYSTEMS USING AN OPTIMIZED PHASE VARYING FUNCTION - A pulsed fiber laser oscillator and laser systems incorporating such laser oscillators are presented. The laser oscillator first includes a light generating module which generates optical pulses having an initial spectral profile. A spectrum tailoring module tailors the initial spectral profile of the optical pulses by imposing a phase variation on each optical pulse according to an optimized phase varying function. The optimized phase varying function has one of a rectified sinusoidal shape, a parabolic shape and a rectified parabolic shape. Laser systems incorporating such oscillators may be of a MOPA configuration, and may further include a nonlinear crystal for frequency conversion or a bulk solid-state amplifier. | 07-14-2011 |
| 20110170163 | SYSTEM AND METHOD FOR THE SPATIAL TAILORING OF LASER LIGHT USING TEMPORAL PHASE MODULATION - Laser systems and methods for providing an output light beam having a target spatial pattern are provided. A light generating module generates an input light beam, whose spectral profile is then tailored by imposing thereon a controllable phase modulation. The obtained spectrally tailored light beam is dispersed, using at least one spatially-dispersive element to provide an output light beam having a spatial profile which is a function of the spectral profile of the spectrally tailored light beam, The phase modulation is selected in view of the spectral profile of the input light beam and of the dispersion characteristics of the at least one spatially-dispersive element so that the spatial pattern of the output light beam matches the target spatial pattern therefor. | 07-14-2011 |
| 20110101848 | FLUORESCENCE-BASED LIGHT EMITTING DEVICE - A light emitting device generates a broadband light beam in response to an excitation light beam. The light emitting device includes a matrix in which is provided a plurality of fluorescent components of different types. Each type of fluorescent component has an absorption spectrum and an emission spectrum respectively differing from absorption and emission spectra of other types of fluorescent components. The matrix and the types, concentration and positioning of the fluorescent components are selected to output the broadband light beam in response to the excitation light beam. The types of fluorescent components may include fluorescent compounds, quantum dots or a combination thereof. The light-emitting device above may be used as a fluorescent standard, or incorporated into a light source. Scattering elements may also be incorporated in the matrix. | 05-05-2011 |
| 20110091150 | EVANESCENT WAVE MULTIMODE OPTICAL WAVEGUIDE AND SENSOR WITH CONTINUOUS REDISTRIBUTION OF OPTICAL POWER BETWEEN THE MODES - There is provided an evanescent wave multimode optical waveguide sensitive to a chemical species or to a physical parameter. The optical waveguide comprises a core and a cladding having a cladding refractive index lower than that of the core for guiding light to be propagated in the optical waveguide. The cladding defines with the core an optical waveguide providing mode coupling. A chemical indicator is provided in the cladding for causing a variation of the optical absorption of the cladding as a function of the chemical species or the physical parameter. The cladding is interrogated by the evanescent wave of the propagated light. The mode coupling causes unabsorbed light power to be redistributed among the multiple modes while light propagates along the optical waveguide. | 04-21-2011 |
| 20110081123 | MULTI-CLADDING FIBER - Multi-cladding optical fibers to be used in the context of fiber amplifiers and fiber lasers are described herein. Embodiments of optical fibers include a rare-earth doped core into which the signal field is to be amplified. The doped core is surrounded by multiple claddings that guide the pump field to be absorbed by the reactive core material. The first cladding has a depressed refractive index to improve high-order mode bending losses without incurring significant fundamental mode bending losses. | 04-07-2011 |
| 20110002348 | ADJUSTABLE PULSEWIDTH PICOSECOND FIBER LASER - A pulsed fiber laser generating light pulses in the picosecond range has an adjustable pulsewidth. The fiber laser includes a figure-of-eight type laser cavity, preferably of polarization-maintaining optical fiber, defining reciprocal and non-reciprocal loops. A gain medium is disposed asymmetrically in the reciprocal loop, at a position therealong favoring coupling of light in the propagation direction of the non-reciprocal loop. A pump source is coupled to the reciprocal loop to inject pump light into the gain medium. The laser cavity is designed so that changing the pump power will directly affect the pulsewidth of the generated light pulses, providing a useful control mechanism of the pulsewidth. | 01-06-2011 |
| 20100324832 | METHOD AND SYSTEM TO MEASURE THE CONCENTRATION OF CONSTITUENT ELEMENTS IN AN INHOMOGENEOUS MATERIAL USING LIBS - A system and method to improve the accuracy of the measure of constituent element(s) in a sample containing domains potentially including the constituent element(s) are described herein. For each domain, the volume of the domain is estimated and the concentration of the constituent element(s) in the domain is determined using LIBS. When all the domains have been analyzed, the volumetric concentration of the domains is summed and divided by the total volume of the sample. Accordingly, by limiting the concentration analysis to separate domains, it is possible to improve the accuracy of the concentration analysis. | 12-23-2010 |
| 20100317966 | Hybrid-multimodal magneto-optical contrast markers - A contrast marker for use in imaging applications, wherein the marker is sensitive to an applied magnetic field through the formation of radical pair species and wherein the marker is independently magnetically sensitive, optically sensitive, and magneto-optically sensitive. | 12-16-2010 |
| 20100316072 | METHODS FOR STABILIZING THE OUTPUT OF A PULSED LASER SYSTEM HAVING PULSE SHAPING CAPABILITIES - Methods stabilize the output of a pulsed laser system using pulse shaping capabilities. In some embodiments, transient effects following a transition between a QCW regime and a pulse shaping regime are mitigated by ensuring that the average QCW optical power substantially corresponds to the average pulsed optical power outputted in a steady-state operation of the pulsed laser system in the pulse shaping regime. The QCW signal or the pulse shaping signal may be adapted for this purpose. In other embodiments, transient effects associated with non-process pulses emitted between series of consecutive process pulses are mitigated through the proper use of sequential pulse shaping. | 12-16-2010 |
| 20100312097 | Hybridized optical-MRI method and device for molecular dynamic monitoring of in vivo response to disease treatment - An apparatus for providing physiological information from an organism in disease diagnosis and treatment monitoring, for use in an MRI instrument. The apparatus operates on the concept of hybridized magneto-optical sensitivity. The MRI includes an MRI scanner and a controller for controlling the MRI scanner. The MRI scanner provides a magnetic field of at least 0.5T. The apparatus further includes a front end built of non-magnetic components, comprising light guides for illuminating a region of interest (ROI) and for collecting light emitted at said ROI; and a back-end comprising a light source for injecting light into said light guides; a light detector for receiving light collected at said ROI; and a processing and control unit for processing said light collected at said ROI. | 12-09-2010 |
| 20100154554 | MICRO-THERMISTOR GAS PRESSURE SENSOR - An apparatus and method precisely measure gas pressure over a large dynamic range and with good immunity to temperature fluctuations, encompassing applications such as gas sensing, bolometer imaging and industrial process monitoring. The micro-thermistor gas pressure sensor assembly includes a suspended platform micro-thermistor sensor device exposed to the gas pressure of a given atmospheric environment, an electrical readout circuit connected to the suspended platform micro-thermistor sensor device, wherein the suspended platform micro-thermistor sensor device acts as a variable electrical resistance in the readout electrical circuit, a binary-wave voltage source connected to the suspended platform micro-thermistor sensor device, and an ohmmeter. | 06-24-2010 |
| 20100154510 | METHOD FOR SENSING GAS COMPOSITION AND PRESSURE - A method for sensing gas composition and gas pressure, based on the thermal constants of a variable electrical resistor, is presented. The method for sensing gas composition and pressure includes monitoring a variable electrical resistor whose dynamic thermal response is determined by the thermal conductivity and thermal capacity of the surrounding gas of a given atmospheric environment. In the thermal domain, the sensor has a low-pass characteristic, whose phase delay is determined by the thermodynamic characteristics of the surrounding gas such as composition and pressure. The method can be used for sensing gas composition and can also be used for sensing gas pressure. | 06-24-2010 |
| 20100135347 | DEVICE AND METHOD FOR GENERATING BURSTS OF PICOSECOND OPTICAL SUB-PULSES - A method and device are provided for generating bursts of sub-pulses, preferably in the picosecond range. Seed pulses are first generated, and then phase modulated to spread their spectral profile to several time-dependent spectral components. The phase modulated seed pulses are then spectrally filtered to remove spectral components and retain only selected ones, creating gaps in the amplitude profile of the seed pulses which therefore form bursts of sub-pulses. Various parameters such as the modulation amplitude, the modulation frequency, the spectral characteristics of the filters and the overall amplitude of the seed pulses may be controlled to provide a great versatility and adaptability. | 06-03-2010 |
| 20100128744 | SPECTRALLY TAILORED PULSED FIBER LASER OSCILLATOR - High power optical pulses generating methods and laser oscillators are provided. A light generating module generates seed optical pulses having predetermined optical characteristics. A spectrum tailoring module is then used to tailor the spectral profile of the optical pulses. The spectral tailoring module includes a phase modulator which imposes a time-dependent phase variation on the optical pulses. The activation of the phase modulator is synchronized with the passage of the optical pulse therethough, thereby efficiently reducing the RF power necessary to operate the device. | 05-27-2010 |
| 20100042362 | DIGITAL SIGNAL PROCESSING IN OPTICAL SYSTEMS USED FOR RANGING APPLICATIONS - Methods and apparatuses for reducing the response time along with increasing the probability of ranging of optical rangefinders that digitize the signal waveforms obtained from the pulse echoes returned from various types of objects to be ranged, the pulse echoes being too weak to allow successful ranging from a single waveform or the objects being possibly in motion during the capture of the pulse echoes. In a first embodiment of the invention, the response time at close range of a digital optical rangefinder is reduced by using a signal averaging process wherein the number of data to be averaged varies with the distance according to a predetermined function. In a second embodiment of the invention, the probability of ranging objects in motion along the line of sight of a digital optical rangefinder is increased and the object velocity measured by performing a range shift of each acquired signal waveform prior to averaging. In a third embodiment of the invention, the signal waveforms acquired in the line of sight of a digital optical rangefinder are scanned over a predetermined zone and range shifted and averaged to allow for early detection and ranging of objects that enter in the zone. | 02-18-2010 |
| 20100040098 | LASER DIODE ILLUMINATOR DEVICE AND METHOD FOR OPTICALLY CONDITIONING THE LIGHT BEAM EMITTED BY THE SAME - A laser diode illuminator device and a method for optically conditioning the output beam radiated from such a device, so that highly-demanding illumination application requirements that call for high output powers within a specified field of illumination can be addressed. At the heart of the device is a two-dimensional stack of laser diode bars wherein the linear array of beamlets radiated by each laser diode bar is optically conditioned through its passage in a refractive-type micro-optics device followed by a cylindrical microlens. The micro-optics device performs collimation of the linear array of beamlets along the fast axis of the bars, and it also acts as a beam symmetrization device by interchanging the divergences of the laser beamlets along the fast and slow axes. The cylindrical microlens is for collimation of the beamlets along the slow axis. The optical conditioning is performed individually for each linear array of beamlets so that the radiance or brightness of the laser diode illuminator can be optimized while any specified field of illumination can be filled with an excellent uniformity of the radiant intensity. | 02-18-2010 |
| 20100039637 | DIGITAL SIGNAL PROCESSING IN OPTICAL SYSTEMS USED FOR RANGING APPLICATIONS - Methods and apparatuses for reducing the response time along with increasing the probability of ranging of optical rangefinders that digitize the signal waveforms obtained from the pulse echoes returned from various types of objects to be ranged, the pulse echoes being too weak to allow successful ranging from a single waveform or the objects being possibly in motion during the capture of the pulse echoes. In a first embodiment of the invention, the response time at close range of a digital optical rangefinder is reduced by using a signal averaging process wherein the number of data to be averaged varies with the distance according to a predetermined function. In a second embodiment of the invention, the probability of ranging objects in motion along the line of sight of a digital optical rangefinder is increased and the object velocity measured by performing a range shift of each acquired signal waveform prior to averaging. In a third embodiment of the invention, the signal waveforms acquired in the line of sight of a digital optical rangefinder are scanned over a predetermined zone and range shifted and averaged to allow for early detection and ranging of objects that enter in the zone. | 02-18-2010 |
| 20100006786 | METHOD AND APPARATUS FOR OPTICAL LEVEL SENSING OF AGITATED FLUID SURFACES - A method and apparatus provide for non-contact optical measurement of the level of a fluid stored in a tank or container, the surface of the fluid being possibly agitated. The method processes numerically the digitized signal waveforms generated by a lidar apparatus based on a pulsed time-of-flight modulation scheme. A key step of the numerical processing is the computation of a waveform in which each data point is obtained from a statistical estimator of the variability of the amplitude signal echo measured at the distance from the lidar apparatus that corresponds to the rank of the data point in the waveform. The statistical estimator is preferably the standard deviation. By using a statistical estimator of the variability of the captured signal amplitude, the specific signal echo returned from an agitated fluid surface can be greatly amplified as compared to the signal echoes returned from any obstacle or medium that could be present along the path of the optical beam radiated by the lidar apparatus. The method then allows for an efficient retrieval of the useful signal echo from which the level of the fluid surface can be reliably measured with greater accuracy, particularly in situations where the useful signal echo would be buried in a strong signal echo returned from any optically scattering or absorbing medium that would fill in the volume of the tank above the fluid surface. | 01-14-2010 |
| 20090323741 | DIGITAL LASER PULSE SHAPING MODULE AND SYSTEM - A digital pulse shaping module for controlling a pulsed laser oscillator according to a digital input waveform is provided. The pulse shaping module includes a clock generator generating a plurality of phase-related clock signals and a shape generator which outputs a digital shape signal corresponding to the digital input waveform in Double Data Rate in response to the clock signals. A DAC converts the digital shape into an analog shape signal. The analog shape signal may be used to control the current source of a laser seed source or modulators in the laser oscillator shaping a seed light signal. Optionally, the pulse shaping module may also output a gate control signal having a predetermined timing relationship with respect to the digital shape signal. | 12-31-2009 |
| 20090198114 | APPARATUS AND METHOD FOR ELUCIDATING REACTION DYNAMICS OF PHOTOREACTIVE COMPOUNDS FROM OPTICAL SIGNALS AFFECTED BY AN EXTERNAL MAGNETIC FIELD - An apparatus and method for elucidating reaction dynamics of photoreactive compounds from time-resolved optical signals affected by an external magnetic field. The apparatus includes a coil or magnet for applying a magnetic field at a region of interest (ROI). The apparatus further includes a light or laser for illuminating the ROI with a probe beam. An optical fiber collects light emitted by the probe beam; and a computer analyses the collected light. | 08-06-2009 |
| 20090141344 | HIGH-RESOLUTION OPTICAL IMAGING SYSTEMS - High-resolution imaging systems are provided. In one embodiment, an imaging system based on a Cassegrain or Schmidt-Cassegrain objective, with coaxial primary and secondary mirrors, is provided with a microdisplacement mechanism acting on the secondary mirror to displace the image on a focusing array. In another embodiment, two co-axial Cassegrain-type objectives are provided one within the other with a common focal plane array, which therefore detects combined wide field-of-view and narrow field-of-view images. | 06-04-2009 |
| 20090119044 | DIGITAL SIGNAL PROCESSING IN OPTICAL SYSTEMS USED FOR RANGING APPLICATIONS - Methods and apparatuses for reducing the response time along with increasing the probability of ranging of optical rangefinders that digitize the signal waveforms obtained from the pulse echoes returned from various types of objects to be ranged, the pulse echoes being too weak to allow successful ranging from a single waveform or the objects being possibly in motion during the capture of the pulse echoes. In a first embodiment of the invention, the response time at close range of a digital optical rangefinder is reduced by using a signal averaging process wherein the number of data to be averaged varies with the distance according to a predetermined function. In a second embodiment of the invention, the probability of ranging objects in motion along the line of sight of a digital optical rangefinder is increased and the object velocity measured by performing a range shift of each acquired signal waveform prior to averaging. In a third embodiment of the invention, the signal waveforms acquired in the line of sight of a digital optical rangefinder are scanned over a predetermined zone and range shifted and averaged to allow for early detection and ranging of objects that enter in the zone. | 05-07-2009 |
| 20090046352 | Low-average-power parabolic pulse amplifiction - There is provided a parabolic pulse amplifier for amplifying a pulse light signal. The amplifier comprises an ytterbium-doped amplification waveguide pumped using a pump source with a pump central wavelength substantially offset from the absorption transition peak wavelength. The pump wavelength is selected such that the absorption coefficient of pump light and the gain coefficient of the signal are substantially equal in the amplification waveguide such that the amplification gain is distributed substantially uniformly along the amplification waveguide. | 02-19-2009 |
| 20080199135 | Archimedean-lattice microstructured optical fiber - A microstructured optical fiber exhibiting enhanced circularity of the guided light mode is provided. The microstructured optical fiber includes a light-guiding core and a primary cladding surrounding the core wherein the primary cladding has a plurality of holes arranged in hexagonal unit cells defining an Archimedean-like lattice. Preferably, the core is defined by a break in a center of the Archimedean-like lattice, the break being characterised by an absence of at least one of the unit cells. Also preferably, each of the unit cells has seven holes arranged in a centred hexagon. A method of making the microstructured optical fiber is also provided. The method includes fabricating a fiber preform by stacking a plurality of canes around a rod, each cane having a number of holes arranged in a unit cell defining an Archimedean-like lattice, and drawing said fiber preform into the microstructured optical fiber. | 08-21-2008 |
