Patent application number | Description | Published |
20090003398 | Light-transmitting module capable of responding a high-frequency over 10GHz - The laser diode of the present invention is mounted on the heat sink made of insulating material such as aluminum nitride (AlN). On the heat sink, a metal film, evaporated gold film, is provided and the laser diode is mounted on the heat sink such that the anode electrode of the laser diode faces and is in contact with the metal film. The heat sink is mounted on the grounded metal member, thus the metal member, the heat sink and the metal film forms an capacitor. The bias for the laser diode is provided via the metal film, thereby stabilizing the bias supply even when the operational frequency for the laser diode is over 10 Gbps. | 01-01-2009 |
20090238226 | DRIVER 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 |
20110019706 | SHUNT 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 |
20120106981 | LASER DRIVER AND OPTICAL TRANSMITTER IMPLEMENTING THE SAME - An LD-Driver with the push-pull arrangement is disclosed. The driver includes the high side driver driven by the positive phase signal and the low side driver driven by the negative phase signal. When the positive phase signal is in HIGH, the high side driver becomes ON and the LD driver provides additional current to the bias current for the LD; while, when the negative phase signal is in HIGH, the low side driver becomes ON and the LD driver extracts a portion of the bias current for the LD. | 05-03-2012 |
20120249241 | LIGHT RECEIVING CIRCUIT WITH DIFFERENTIAL OUTPUT - A trans-impedance amplifier (TIA) for a light-receiving circuit is disclosed where the TIA reduces the power consumption as suppressing the degradation of the signal quality in high frequency regions. The TIA comprises a primary core, a dummy core, and a differential amplifier that receives each output of two cores in the differential mode. Two cores have an arrangement substantially same to each other except that the power consumption thereof is smaller in the dummy core. Because the output impedance of two cores becomes substantially equal, the scattering parameter of the common mode to the differential mode at the output of the primary core becomes small enough. | 10-04-2012 |
20130016745 | DRIVER FOR LASER DIODE INTEGRATED WITH EXTERNAL MODULATORAANM MOTO; AkihiroAACI Yokohama-shiAACO JPAAGP MOTO; Akihiro Yokohama-shi JP - A driver for EA-DFB device is disclosed. The EA-DFB device is put between the positive power supply and the negative power supply as connected in series to the bias current source and the switching device. The EA device is modulated by the switching device in the differential mode. The switching device includes paired transistors each having a load, one of which is a resistor connected in parallel to the EA device, while, the other is constituted by a resistive element. | 01-17-2013 |
20130156056 | SHUNT 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 |
20130195133 | DRIVER 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 |
20130229231 | DIFFERENTIAL CIRCUIT COMPENSATING GAIN ENHANCEMENT DUE TO SELF HEATING OF TRANSISTORS - A differential circuit with a function to compensate the gain enhancement due to the self-heating of the transistor is disclosed. The differential circuit includes an equalizer unit coupled with one of paired transistors. The other of the paired transistor receives the input signal to be amplified. The base level, or the base-emitter bias, is oppositely modulated by the input signal through the common emitter, which causes the modification of the base current. The equalizer unit reduces the variation of the base level only in low frequencies where the self-heating effect of the transistor appears. | 09-05-2013 |
20140126596 | OPTICAL TRANSMITTER SUPPRESSING EXCESS EMISSION OF LASER DIODE - A laser diode (LD) driver to suppress the excess emission of an LD is disclosed. The LD driver has the shunt configuration with a driving transistor connected in parallel to the LD to shunt the bias current provided to the LD. The driver further provides a protection circuit to divide the bias current when the bias current is active but the driving transistor is turned off at an instant of the power on and off of the LD driver. | 05-08-2014 |