| 摘要 |
PROBLEM TO BE SOLVED: To provide a simple wavelength detecting device of a low cost for severely managing wavelengths of respective signal lights in which wavelength intervals are approached particularly in a wavelength multiplex optical communication system. SOLUTION: The wavelength detecting device comprises an optical path dividing element 35 for dividing one propagating light into at least three propagating lights having different optical path angles, and one wavelength selecting element 36 for filtering and outputting the lights given from the element 35 in different predetermined wavelengths. In this case, one of the propagated lights of the predetermined wavelength filtered and output from the element 36 is output as a signal light, and the other propagated lights of the different predetermined wavelengths are used as for a monitoring lights for detecting the wavelength. |
