| 摘要 |
PROBLEM TO BE SOLVED: To provide a wavelength selection switch capable of reducing minus first-order light incident to light input/output ports.SOLUTION: A wavelength selection switch 1A includes a light input/output part 18 including an input port 11 and output ports 12a-12d, a wavelength dispersion element 15, and an LCOS-type phase modulation element 17. Each first-order light of wavelength components L21-L23 diffracted by the phase modulation element 17 is incident to the desired output ports 12b-12d, respectively. The input port 11 and the output ports 12a-12d are arranged so that the output ports 12a-12d and an optical axis of minus first-order light of the wavelength components L21-L23 separate from each other. |
