| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical digital reproducing device which reproduces an optical pulse signal with much higher reliability while keeping it as light, unnecessitates a high speed photodiode, improves reliability and reduces the cost. SOLUTION: Signal light (wavelength λi) from a main line system is inputted from a light input terminal 30 to a wavelength converter 32. In the wavelength converter 32, signal light and CW probe light wavelength λj) from a probe light source 38 are made incident on an EA modulator 36. The probe light outputted from the EA modulator 36 is equipped with a waveform reflected with the waveform of the signal light, and supplied to a wavelength converter 46 by a light circulator 34. Besides, the EA modulator 36 generates a photo current reflected with the intensity fluctuation of incident signal light and a clock extracting circuit 40 extracts a clock component from that photo current. In the wavelength converter 46, a probe light source 52 generates the probe pulse light (wavelength λk) of a clock frequency extracted by the clock extracting circuit 40 and an LD amplifier 50 superimposes the waveform of signal light (λj) from the wavelength converter 32 to the probe pulse light (λk). |
