| 摘要 |
PURPOSE:To apply direct waveform shaping to an optical signal with simple constitution by providing an optical branching device, a phtotoelectric converter, an optical amplifier, an input optical path and an electric circuit, modulating an optical signal by an electric signal to apply waveform shaping. CONSTITUTION:An optical signal inputted from an optical fiber is branched by an optical branching device 20. One branched optical signal is converted into an electric signal by a photoelectric converter 22, and the electric signal and the other branched input are given respectively via an electric circuit 28 and an input optical path 26 to an optical amplifier 24 whose gain is made variable by the electric signal. The timing of the optical signal and the electric signal given to the optical amplifier 24 has nearly the same and the optical amplifier 24 is used to modulate the optical signal by the electric signal to apply waveform shaping to the input optical signal and the result is outputted to the optical fiber 18. Thus, the optical signal is subject to direct waveform shaping with simple constitution without using an electrooptic converter and the waveform distortion or the deterioration in the response speed in the electrooptic converter are prevented to attain high speed response. |
