Light output stabilizing circuit

Abstract

Abstract PURPOSE:To prevent the deterioration of the light receiving characteristics of a light receiver by maintaining the light erasing ratio constant while holding the light output of a semiconductor laser constant. CONSTITUTION:An input signal of a terminal 7 is converted from voltage to current by a pulse drive circuit 1, and superposed with the bias current of a semiconductor laser 3 in a motor driven superposing circuit 2. The laser 3 is driven by the current to obtain a light output at the terminal 8. The monitoring light from the laser outputted from a terminal 3-1 is converted to a current by a photoelectric converter 4, a signal component is detected by a signal component detector 5 with the current, compared with the reference voltage by a bias current control circuit 6, and amplified, thereby controlling the bias current. As a result, the light output of the laser is stabilized. The output of the converter 4 is applied via a mean value detector 9 to a signal pulse current control circuit 11. The circuit 11 compares it with the signal of the mean value detector 10 to control the signal pulse current, thereby maintaining the light erasing ratio constant.

Inventors

• 👤 Nobumi Kuriyama
• 👤 宜巳 栗山

Bibliographic Details