System of tunable metasurface

A system of a tunable metasurface, wherein the system of the tunable metasurface comprises:

• a wavefront modulator, an optical focusing device, a metasurface;
• the metasurface comprises a plurality of nanostructures made of a phase change material, and a phase change state of the phase change material comprises a crystalline state and an amorphous state;
• the wavefront modulator is set on a side of the optical focusing device that is far away from the metasurface;
• and the wavefront modulator is configured to modulate a wavefront aberration of incident control lights and emit the control lights after wavefront modulated towards the optical focusing device;
• the optical focusing device is configured to focus wavefront-modulated control lights to form a plurality of focal points;
• the metasurface is set on a focal plane formed by the plurality of focal points, and at least some nanostructures correspond to positions of the plurality of focal points;
• the metasurface is configured to modulate a phase of an incident working light, and an optical path of the working light does not overlap with the wavefront modulator and the optical focusing device.