| 摘要 |
PURPOSE:To stabilize the light pulse peak value of a laser diode with respect to temperature change and also the operation of a bias current control circuit therefor by newly adding a pulse modulator circuit with a pulse modulator current source having predetermined temperature characteristics. CONSTITUTION:A laser diode 1 is connected to a bias current control circuit 3 having a photodiode 2, and connected optically to the photodiode 2 using an optical system. Thus, a pulse modulation current is applied to a supply terminal 5, supplied to the connecting point of the laser diode 1 and the circuit 3. At this time a pulse modulation current source 6 is interposed therebetween, at predetermined temperature characteristics. Thus, when the light emitting efficiency of the laser diode 1 is altered by the temperature change, the source 6 controls the value of the modulated current, thereby retaining always the light pulse peak value constant. |
