Optical clock signal extraction device and optical clock signal extraction method

Abstract

The present invention is an optical clock signal extraction device and method which extracts optical clock signal independent of the polarized light direction of the input light signal. The apparatus comprises first conversion means and second conversion means for enabling to extract an optical clock signal without depending on the polarization direction of an input optical signal. The first conversion means comprises a first optical converter and a continuous wave light source of which wavelength is lambda2, where an input optical signal of which wavelength is lambda1 and continuous wave light of which wavelength is lambda2 are input to the first optical converter, and an intermediate optical signal of which wavelength is lambda2 is generated and output without depending on the polarization direction of the input optical signal. The second conversion means has a second optical converter, where the intermediate optical signal is input to the second optical converter, and an optical clock signal of which wavelength is lambda3 is generated and output by the passive mode locking operation of the second optical converter. The input optical signal is input from the end face L 1 of the first optical converter, and the continuous wave light of which wavelength is lambda2 is input to the first optical converter from the other end face of the first optical converter. The intermediate optical signal is output from the end face of the first optical converter and input to the end face of the second optical converter. The optical clock signal is output from the other end face of the second optical converter.

Description

technical field [0001] The present invention relates to an optical clock signal extraction device for optical repeaters and the like used in long-distance and large-capacity optical fiber communication systems, in particular to a device for extracting fast optical clock signals exceeding the upper limit operating speed of electronic equipment. Background technique [0002] Long-distance and large-capacity transmission of optical communication networks have been developed. As the transmission distance increases, optical loss in the optical transmission path, a decrease in the S / N ratio due to the use of multiple stages of optical amplifiers, and the dispersion of the group velocity of the optical fiber or nonlinear optical effects in the optical fiber occur. Waveform distortion causes a problem of deterioration in the quality of an optical signal due to the above-mentioned circumstances. The occurrence of frequency waveform distortion and time waveform distortion becomes a m...

AI Technical Summary

Problems solved by technology

[0018] Therefore, when the polarization direction of the input optical signal changes for some reason, the optical clock signal cannot be extracted stably.

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