| 摘要 |
PROBLEM TO BE SOLVED: To provide a drive circuit for laser diode that can ensure proper falling characteristics, while inhibiting relaxation vibration. SOLUTION: A differential amplification circuit 2 for driving an LD 4 comprises a pair of transistors 21 and 22, where an emitter is connected commonly and at the same time, a laser diode is connected to one output end, and a current source 23 that is connected to the emitters. A waveform-shaping circuit 1 is connected to the base of the transistors 21 and 22. The waveform- shaping circuit 1 sets the rising time for preventing relaxation vibration from being generated at rising of the drive current, and carries out waveform shaping at falling of the drive current so that the falling waveform of the drive current becomes steep. |
