| 摘要 |
PURPOSE:To prevent fluctuatons in the amount of emitted light of laser diode caused by fluctuations of power and voltage. CONSTITUTION:An input voltage V1 corresponding to the amount of emitted light of a laser diode 11 gained using a monitor diode 12 is converted into current by current-voltage conversion amplifiers 31 and 32, this current is compared with a reference value by a current-voltage conversion amplifier 33 and converted into an output voltage V2 with a power voltage Vcc as a reference. A light is emitted by the laser diode 11 in the amount of emitted light corresponding to a potential difference between the power voltage Vcc and the output voltage V2 of an APC circuit 30. Thus, since the power voltage Vcc is used as reference for the output voltage V2, no influence of the fluctuations in the power voltage Vcc is given to the amount of emitted light of the laser diode 11. |
