| 摘要 |
PURPOSE: To attain highly accurate optical output control by judging whether transmitting data are optical outputs or not. CONSTITUTION: A photodiode PD monitors output light from a laser diode LD and sends a current signal. The current signal is converted into a voltage signal by an I/V conversion circuit 11. A timing extracting circuit 14 generates a transmitting timing signal in accordance with transmitting data and a clock signal. A level judging circuit 12 compares the voltage signal with a previously set voltage level to obtain a compared result, judges the level of the compared result at timing indicated by the timing signal and outputs a control signal. A V/I conversion circuit 13 applies a driving current to the laser diode LD in accordance with the control signal. |
