Light output stabilizing circuit of semiconductor laser

Abstract

Abstract PURPOSE:To keep constant the optical output, by detecting simultaneously the peak value and average value of the monitor light of the semiconductor laser, and by respectively controlling the laser signal current with the peak value signal and the DC bias current of laser with the average signal. CONSTITUTION:The stabilizing circuit is constituted with the signal drive circuit 1 inputting modulation signal, DC bias circuit 2 operating the DC bias current for semiconductor laser drive, semiconductor laser 3, photo detector 4, circuit 5 detecting the average value of the monitor light of semiconductor laser, and circuit 6 detecting the peak value. With this constitution, the monitor light is received with the photo detector by operating the laser 3, and the drive signal of laser 3 is controlled by detecting the peak value with the circuit 6. On the other hand, the average value of monitor light is detected with the circuit 5 at the same time, and the Dc bias current of the laser 3 is controlled by using this information. Thus, the peak value of light pulse is made constant even to the deterioration of the laser 3 and the variation in ambient temperature.

Inventors

• 👤 Yukio Minami

Bibliographic Details