Optical switch and method for controlling optical switch

An optical switch, comprising:

• a mirror to reflect an input light;
• a controller to generate a control signal according to path information selecting an output optical fiber to which a reflected light from the mirror is guided out of a plurality of output optical fibers;
• a generator to generate a low-frequency signal;
• an adder to superimpose the low-frequency signal on the control signal;
• a driver to drive the mirror with a drive voltage corresponding to the control signal on which the low-frequency signal is superimposed;
• a detector to detect a frequency component or a harmonic component of the low-frequency signal included in the reflected light from the mirror;
• and
• a correction unit to correct the control signal based on a detection result by the detector, wherein
• the generator determines an amplitude of the low-frequency signal according to the path information.

A method for controlling an optical switch that includes a mirror configured to reflect an input light, comprising:

• generating a control signal representing a target rotation angle of the mirror;
• generating a low-frequency signal having an amplitude determined according to the target rotation angle;
• superimposing the low-frequency signal on the control signal
• rotating the mirror with a drive voltage corresponding to the control signal on which the low-frequency signal is superimposed;
• detecting a frequency component or a harmonic component of the low-frequency signal included in an output light reflected by the mirror;
• and
• correcting the control signal based on the detection result of the frequency component or the harmonic component of the low-frequency signal.