OPTICAL CLOCK EXTRACTION METHOD AND APPARATUS

摘要

An optical clock signal extraction method and a device are provided to exactly select wavelength components only which are necessary for restoration of clock signals from received optical signals, thereby reducing influence by noise on a restored clock as minimizing size differences between clock signals in accordance with time. A wavelength selector(30) basically extracts the first and second wavelength signals of pre-designated wavelengths to extract clock components from inputted optical signals. An optical amplifier(35) amplifies the selected/outputted first and second wavelength signals. A Fabry-Perot filter(36) passes pre-designated first and second wavelength components only among the amplified signals. An SOA(Semiconductor Optical Amplifier)(37) operates in a saturated area, and controls the signals outputted from the filter(36) in predetermined size.