Drive circuit for semiconductor laser

Abstract

Abstract PURPOSE:To operate a semiconductor laser device with a single power supply by connecting the serial circuit of the light sensitive element and a resistance which are coupled to a semiconductor laser element to the transistor for driving said laser element. CONSTITUTION:The P type electrode side of a semiconductor laser 1 is connected to the plus power source which is a single power supply, while the N type electrode side is connected to the transistor TRQ1. A serial circuit of the TRQ1 and resistor R1 is connected in parallel with a serial circuit of the photo-coupled PIN photo diode 2 and the resistor R2. The operational amplifier OP1 is provided for controlling a light emitting output of the laser 1 with a photo current generated on the diode 2, an optical output of the diod 2 is given to the inversion terminal, while the reference voltage V1 is given to the non-inverting terminal. An output of OP1 is given to the base of TRQ1, and the collector current of TRQ1, namely the drive current of laser 1 is controlled so that an output of light sensitive element corresponding to the level preset by the voltage V1 can be obtained.

Inventors

• 👤 Kazuhisa Murata
• 👤 和久 村田
• 👤 Jiyunji Inada
• 👤 順史 稲田

Bibliographic Details