| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a wavelength selection switch capable of improving the degree of freedom in optical design.SOLUTION: The wavelength selection switch includes: a port array formed by arranging, in a first direction, input ports for inputting signal light and output ports for outputting the signal light; a spectroscopic element for dispersing the signal light inputted from the input port into a second direction different from the first direction; a condensing element for condensing the respective signal light dispersed at the spectroscopic element; a deflecting element for deflecting the respective signal light condensed at the condensing element, toward the output ports; a first optical system for setting a beam waist position of the signal light incident on the condensing element, to a focus of the condensing element in an optical axis direction, in a first plane spreading in the first direction and the optical axis direction of the signal light; and a second optical system for shifting the beam waist position of the signal light incident on the condensing element, from a front side focus in the optical axis direction, in a second plane spreading in the second direction and the optical axis direction.</p> |
