| 摘要 |
PURPOSE:To shift the laser output of the semiconductor laser device always at an adequate value by employing a photodetector and a heat-sensitive element. CONSTITUTION:Resistor 6 is connected in series with the photodetector 5 for receiving the back beam of the semiconductor laser element 1, and the heat-sensitive element 3 is connected in parallel with the photodetector 5 and the resistor 6. The input IN1 of the error amplifier is connected to the terminal T1 of the detector 5, and a reference voltage source 8 is connected between the input IN2 and the terminal T2 of the error amplifier 7. When the back beam from the laser element 1 is irradiated to the photodetector 5, a current I1 flows to feed back a signal to a laser drive circuit 9 for driving the laser element 1, and the current applied to the laser element 1 is controlled. |
