| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical waveform digitizer performing digital processing of an analog optical waveform signal of an ultrahigh speed. SOLUTION: An NOLM (nonlinear optical loop mirror) type optical analog-digital conversion apparatus includes an optical sampling system (50) and an optical quantization/coding device (40). The optical sampling system (50) performs optical sampling of an ultrahigh-speed analog optical waveform signal. In order to reduce the duty ratio of the sampling optical signal, the optical serial-parallel conversion apparatus 30 is coupled between the optical sampling system (50) and the optical quantization/coding device (40). Based on the coupling form, the optical quantization/coding device (40) is composed of a plurality of N bit optical quantization/coding devices (42) which are coupled to the respective channel outputs of the optical serial-parallel conversion apparatus 30. The output of each N bit optical quantization/coding device (42) is handed over to a determination circuit and memory unit (60) which are electric circuits. In an alternate form, an optical amplifier with an ALC function for controlling the average power of the sampling optical signal input to the optical quantization/coding device (40) to approximately constant is provided. COPYRIGHT: (C)2008,JPO&INPIT
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