| 摘要 |
PROBLEM TO BE SOLVED: To measure a correlation between an optical signal and a reference bit pattern without performing clock extraction by phase-modulating probe light by using an interaction between wavelengths in a non-linear optical refraction medium of the probe light and the signal light. SOLUTION: A part of a signal light traveling to a spectroscope 102-1 is branched and becomes probe light going to an optical multiplexer/demultiplexer 103-1. The signal light and the probe light are made incident to a Mach-Zehnder interferometer from a reverse direction via an optical multiplexer/demultiplexer 103-2 and an optical multiplexer/demultiplexer 103-3, respectively. A non-linear refraction area on the upper arm of the interferometer corresponds to 1 of a reference bit pattern, and a non-linear refraction are on the lower arm corresponds to 0 of the reference bit pattern. On each arm, a phase change according to the correlation between a buried non-linear pattern and a signal pattern is impressed on the probe light. When the probe light from both arms are made to interfere each other, an interferometer output is obtained according to a difference between the phases impressed in the upper arm and the lower arm. |
