| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical transmission circuit capable of controlling optical transmission power to be constant over plural burst signals in the case of converting burst-shaped electric signals to optical signals. SOLUTION: This optical transmission circuit is provided with an LD 21 for emitting an optical signal with strength corresponding to transmission light power, PD 22 for outputting a photocurrent corresponding to the transmission light power of the LD 21, I/V 2 for converting the photocurrent from the PD 22 to an electric signal corresponding to transmission light power, S/H 3 for converting the electric signal to a digital signal and holding it, D-AVE 4 for performing averaging processing on plural digital signals, D-APC 5 for comparing the set value of prescribed transmission light power with the output signal of the D-AVE 4 and generating an up signal or a down signal, D-CNT 6 for generating a signal for driving a semiconductor laser corresponding to the up or down signal, a burst control signal, a clock signal and a data signal, and LD-DRV 7 for controlling the driving current of the LD 21 corresponding to the output signal of the D-CNT 6. |
