System for regulating optical output power
Systems and methods for regulating optical power are described. A system for regulating optical power includes a laser driver circuit that receives an enable/disable signal and a data modulator input. The enable/disable signal regulates asynchronous mode operation. The system also includes a laser module including a laser diode emitter and a photodiode detector. The laser module is coupled to the laser driver circuit and receives a laser bias current from the laser driver circuit. The system also includes a switch coupled to the photodiode to receive a signal from the photodiode detector. The system also includes an automatic power control (APC) feedback circuit that receives a signal from the switch and provides a laser bias current feedback signal to the laser driver circuit to compensate for power output changes in the laser diode emitter over time.
1. A system for regulating optical power, comprising:
a laser driver circuit receiving an enable/disable signal and a data modulator input, the enable/disable signal to regulate asynchronous burst mode operation;
a laser module coupled to the laser driver circuit, the laser module including a laser diode emitter and a photodiode detector, the laser module receiving a laser bias current from the laser driver circuit;
a switch coupled to the photodiode detector, the switch receiving the enable/disable signal and a signal from the photodiode detector; and
an automatic power control (APC) feedback circuit receiving a signal from the switch and providing a laser bias current feedback signal to the laser driver circuit to compensate for power output changes in the laser diode emitter over time.
2. The system according to claim 1 , wherein the enable/disable signal is active for a burst mode of less than about 5 μs.
3. The system according to claim 1 , wherein the APC feedback circuit includes an integrating amplifier circuit including an amplifier and a capacitor.
4. The system according to claim 3 , wherein the amplifier circuit maintains the feedback signal when the switch is in the open position.
5. The system according to claim 4 , wherein the APC feedback circuit feedback signal is responsive to changes in the signal from the photodiode detector.
6. The system according to claim 1 , further including a signal level converter coupled to the laser driver circuit for converting the enable/disable signal.
7. The system according to claim 1 , wherein the APC feedback circuit compensates for temperature changes.
8. A system for regulating optical power, comprising:
a laser driver circuit receiving an enable/disable signal and a data modulator input, the enable/disable signal to regulate asynchronous burst mode operation;
a laser module coupled to the laser driver circuit, the laser module including a laser diode emitter and a photodiode detector, the laser module receiving a laser bias current from the laser driver circuit;
a switch coupled to the photodiode, the switch receiving the enable/disable signal and a signal from the photodiode detector; and
a means for generating automatic power control (APC) feedback by receiving a signal from the switch and providing a laser bias current feedback signal to the laser driver circuit to compensate for laser power output changes over time.
9. The system according to claim 8 , wherein the means for generating APC feedback includes an integrating amplifier circuit including an amplifier and a capacitor.
10. The system according to claim 9 , wherein the amplifier circuit maintains the feedback signal when the switch is in the open position.
11. The system according to claim 8 , wherein the means for generating APC feedback circuit compensates for temperature changes.
12. A method of regulating optical output power, comprising:
receiving a data modulation input signal at a laser driver circuit;
receiving an enable/disable signal at a switch and the laser driver circuit, the enable/disable signal to regulate asynchronous burst mode operation;
receiving a laser bias current at a laser module having a laser diode emitter and a photodiode detector;
receiving the enable/disable signal and a signal from the photodiode detector at a switch;
receiving a signal from the switch at an automatic power control feedback circuit; and
providing a laser bias current signal to the laser driver circuit from the automatic power control feedback circuit to compensate for power output changes of the laser diode emitter over time.
13. The method according to claim 1 , further including compensating for temperature changes.
14. The method according to claim 1 , wherein the laser driver circuit uses the laser bias current feedback signal to adjust the laser bias current.