| 摘要 |
PURPOSE:To stabilize the output of a semiconductor laser by applying a reference voltage to one input of an amplifier, and connecting the connecting point of the semiconductor laser to a compensating resistor to the other input terminal of the amplifier. CONSTITUTION:Since a reference voltage VK which is produced from a constant-voltage power source REG is applied to a non-inverting input terminal of an operational amplifier OP1 and the voltage of the connecting point of a semiconductor laser LD and a circuit 12 formed of a compensating resistor is fed back to the inverting input terminal of the amplifier OP1, the voltage of the connecting point of a semiconductor laser LD and the circuit 12 is fixed to the voltage VK, and the forward current of the semiconductor laser LD is specified by the current which is flowed to the compensating resistor group of the circuit 12. When the environmental temperature varies to T1, T2, the resistance value of the temperature compensating resistor group is varied so that the forward current of the laser LD becomes IA1, IA2 so as to stabilize the light output of the laser LD to L. |
