Optical switch and method of adjusting optical switch

An optical switch comprising:

• an input port from which a multiplexed optical signal is input;
• a dispersing unit that disperses the multiplexed optical signal into a plurality of optical signals;
• a converging unit that converges the dispersed optical signals;
• a plurality of mirrors that reflect the converged optical signals, respectively;
• and
• a plurality of output ports through which the reflected optical signals are output, respectively, wherein
• each of the mirrors rotates about a first axis and a second axis to change a first reflection angle and a second reflection angle thereof, respectively, and has a concave reflective surface having a predetermined curvature about the second axis about which each of the mirrors rotates for switching between the output ports, and
• the optical switch further comprises a control unit that controls the first reflection angle of each of the mirrors such that transmissivities of wavelengths included in each of the optical signals output from the output ports become substantially the same, and controls the second reflection angle of each of the mirrors such that a transmissivity of each of the optical signals output from the output ports becomes a desired level.