| 摘要 |
PROBLEM TO BE SOLVED: To provide a wavelength variable type optical filter which selects two or more wavelength components in an arbitrary combination. SOLUTION: This optical filter is constituted of an optical circulator 11 having an input end to which a wavelength multiplexed optical signal in which plural optical signals having different wavelengths are multiplexed is inputted, an output end from which an optical signal having a specific wavelength in the wavelength multiplexed optical signals is outputted and an input-output end for emitting the wavelength multiplex optical signal and for making the optical signal having the specific wavelength enter, a (1×N) optical switch 12 selecting one optical path among respective optical paths connecting a single input-output end to be connected to the input and output ends and N pieces of output ends, N pieces of optical gratings 13 whose one ends are connected respectively to N pieces of output ends of the optical switch 12 and which reflect respectively different specific wavelength components and an (N×1) optical switch 15 selecting one optical path among respective optical paths connecting the N pieces of input ends which are connected respectively to the N pieces of output ends of the N pieces of the gratings and a single output end outputting the wavelength multiplexed optical signal except for the arbitrary specific wavelength. |
