| 摘要 |
PURPOSE:To entirely eliminate the possibility that the reverse direction voltage above a reverse direction rated voltage caused by the supply of a high-frequency current which is a current for modulation, is impressed on a laser diode from the start time of the operation of an APCA loop. CONSTITUTION:The timing to start the supply of a modulation current signal IUHF from an oscillation circuit 32 to the laser diode LD is set by a delay circuit 60 at the point of the time when a bias current signal Ibias attains a specified value or above; in other words, a light output voltage signal fapc attains a set empirical value or above, after the operation of the automatic light output control loop by an APC control circuit 31 is started. The possibility that the reverse direction voltage above the reverse direction rated voltage caused by the supply of the modulation current signal IUHF is applied to the laser diode LD, is then entirely eliminated. |
