| 摘要 |
PROBLEM TO BE SOLVED: To measure wavelength of reflected light from an optical fiber Bragg grating element (FBG). SOLUTION: A wavelength measuring and processing instrument for the reflected light from the FBG is provided with a narrow-band filter 1 which only selectively transmits the wavelength required for the reflected light from the FBG, a wavelength scanning and control unit 4 which only scans the wavelength selectively passed through the filter 1 within a prescribed wavelength range, and a photodetecting and processing section 2 which detects the reflected light passed through the filter 1 and converts the detected light into an intensity value. The instrument is also provided with a smoothing differential filter section 5 which finds a differential coefficient value by smoothing and differentiating the intensity value, a computing section setting section 6 which sets a continuous zero-level flat section between an area where the differential coefficient value becomes a threshold H or higher and another area where the differential coefficient value becomes another threshold L or lower as a computing section, and a weighted-mean calculating section 32 which calculates center wave length of the reflected light based on the intensity value and the weighted mean of scanned wavelength values in the computing section. COPYRIGHT: (C)2003,JPO
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