| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the detection resolution and the detection accuracy for wavelengths. SOLUTION: In a wavelength-measuring apparatus, a reflecting light from each FBG on an optical fiber is brought into an AWG in which a center wavelength can be separated to a plurality of wavelength of minute intervals. At the same time, light-receiving elements connected respectively to a plurality of output channels of the AWG are made corresponding to the FBG by every pair, so that the wavelength of the reflecting light measured on the basis of a logarithm of a ratio of output signals by the pair of the light-receiving elements. The apparatus is provided with an output channel for detecting a noise light which is set separately from the plurality of output channels of the AWG and, a light-receiving element connected to the output channel. The wavelength of the reflecting light is measured on the basis of a logarithm of a ratio of signals obtained by subtracting an error component by the output signal of the light-receiving element connected to the output channel for detecting the noise light from each of output signals of the pairing light- receiving elements corresponding to the FBG.</p> |
