The invention discloses an adjustable topology valley topology
photonic crystal filter with any
wavelength notch. The filter comprises a
waveguide interface, a first valley topology
photonic crystal and a second valley topology
photonic crystal. The first valley topology photonic
crystal comprises a plurality of first regular hexagonal unit cells, fan-shaped
dielectric cylinders are arranged at three
interphase vertexes of a single first regular hexagonal unit
cell, and the first regular hexagonal unit cells are arranged in a
honeycomb array to obtain N circular
dielectric cylinders with the
radius of R; the second valley topology photonic
crystal comprises a plurality of second regular hexagonal unit cells; fan-shaped
dielectric cylinders are arranged at three
interphase vertexes of a single second regular hexagon unit
cell, and the valley number symbols of the fan-shaped dielectric cylinders are opposite to the valley number symbols of the first regular hexagon unit cells; the second regular hexagonal unit cells are arranged in a
honeycomb array to obtain M circular dielectric cylinders, the
radius of the M1 circular dielectric cylinders is R, the
radius of the M2 circular dielectric cylinders is larger than R, and M1 + M2 = M. According to the invention, any
wavelength interval wave
trapping function can be realized.