| 摘要 |
PROBLEM TO BE SOLVED: To enable reception of laser beam having prescribed intensity, even when the lengths of optical fibers are different. SOLUTION: After the laser beam sent from the side of a communicating party is received by a photodiode 8 and amplified by an amplifier part 9, the signal peak is detected by a peak hold part 31. A differential amplifier part 33 finds the difference between the output signal of the peak hold part 31 and a reference level (Rx.Ref), generates a control signal, based on the difference and outputs it through a selector 38 to an auto-power control(APC) 5. The APC 5 drives a laser diode(LD) driving part 2 corresponding to the output from a photodiode 4, to which one part of laser beam emitted from an LD 1 is made incident, and the signal outputted from the differential amplifier part 33. The LD driving part 2 drives the LD 1 by amprifying transmission data (Tx.Data) corresponding to the signal which is outputted from the APC 5. |
