| 摘要 |
PURPOSE:To enable to follow the semiconductor laser to transient laser modulation by controlling the temperature of the laser chip so that a temperature detecting diode provided on the same chip as the laser becomes constant in the forward voltage drop, thereby accelerating the temperature control. CONSTITUTION:The semiconductor laser 17 is formed of a laser and a diode 20 on the same chip, and driven by a laser drive circuit 16. The forward voltage drop of the diode 20 is amplified by a level shift amplifier 22, and connected to a power amplifier 23. The amplifier 23 controls the Peltier element 24. The element 24 and the laser 17 are thermally coupled. A loop having the diode 20, the amplifiers 22 and 23 and the Peltier element 24 forms a negative feedback loop. When the temperature of the diode 20 is raised to cause the forward voltage drop to be reduced, the temperature of the Peltier element 24 is lowered. |
