Optical switch

An optical switch, comprising:

• an optical input-output port that includes three or more ports to which light is input from outside or from which light is output to the outside, the three or more ports being arranged along a predetermined arrangement direction;
• a spatial optical modulator, that includes a light incident layer, a light reflective layer, and a spatial optical modulation layer disposed between the light incident layer and the light reflective layer, spatially modulates light entering the light incident layer from any port of the optical input-output port, and outputs the light spatially modulated toward any of other ports of the optical input-output port;
• and
• a condensing lens, that is disposed between the optical input-output port and the spatial optical modulator, optically couples the optical input-output port and the spatial optical modulator, wherein
• x2≠2x1+x0 holds where:
• a coordinate axis is set along the predetermined arrangement direction of the optical input-output port and a position of an optical axis of the condensing lens is set as an origin of the coordinate axis;
• x0, x1, and x2 respectively are coordinates, in the optical input-output port, of a first port to or from which light is input or output, and a second port and a third port from or to which light input to or output from the first port is output or input;
• and
• x1 and x2 are greater than zero, and
• the coordinate x0 of the first port is zero, and intervals between adjacent ports in the optical input-output port are unequal.

An optical switch, comprising:

• an optical input-output port that includes three or more ports to which light is input from outside or from which light is output to the outside, the three or more ports being arranged along a predetermined arrangement direction;
• a spatial optical modulator, that includes a light incident layer, a light reflective layer, and a spatial optical modulation layer disposed between the light incident layer and the light reflective layer, spatially modulates light entering the light incident layer from any port of the optical input-output port, and outputs the light spatially modulated toward any of other ports of the optical input-output port;
• and
• a condensing lens, that is disposed between the optical input-output port and the spatial optical modulator, optically couples the optical input-output port and the spatial optical modulator, wherein
• i x2 ≠2x1+x0 holds where:
• a coordinate axis is set along the predetermined arrangement direction of the optical input-output port and a position of an optical axis of the condensing lens is set as an origin of the coordinate axis;
• x0, x1, and x2 respectively are coordinates, in the optical input-output port, of a first port to or from which light is input or output, and a second port and a third port from or to which light input to or output from the first port is output or input;
• and
• x1 and x2 are greater than zero, and
• the optical input-output port includes three or more wavelength multiplexer-demultiplexers, and each port that outputs a same wavelength in each of the three or more wavelength multiplexer-demultiplexer forms ports arranged in the predetermined arrangement direction and functions as a wavelength selecting optical switch.