Wavelength selective switch and related optical device

An optical device, comprising a wavelength selective switch, the wavelength selective switch comprising:

• a 2D fiber array, comprising a first column of fibers and a second column of fibers, wherein fibers in the second column of fibers and fibers in the first column of fibers are alternately arranged in a switching direction, the second column of fibers is offset from the first column of fibers by a predetermined spacing in a dispersion direction, the dispersion direction is perpendicular to the switching direction, any fiber in the 2D fiber array is suitable for serving as an input port, and any other fiber is suitable for serving as an output port;
• a first optical path adjustment component, configured to adjust a propagation direction of a first beam from the input port;
• a dispersion unit, configured to disperse the first beam from the first optical path adjustment component, to generate a plurality of first sub-beams corresponding to different wavelengths;
• and
• an optical switching engine, configured to:
• receive the plurality of first sub-beams, and operatively adjust directions of the plurality of first sub-beams, for the plurality of first sub-beams to be incident back to the dispersion unit, wherein
• the dispersion unit is further configured to:
• multiplex at least a part of incident-back first sub-beams that are in the plurality of first sub-beams and that are of desired wavelengths, to generate a multiplexed second beam, and guide the second beam to the output port via the first optical path adjustment component.