The invention provides an optical bistable device based on an optical Tamm state and application of the optical bistable device. The optical bistable device comprises a
metal substrate layer, a transparent
conductive oxide film and a
photonic crystal layer, wherein the transparent
conductive oxide film and the
photonic crystal layer are sequentially arranged on the
metal substrate layer; the
photonic crystal layer comprises x unit
cell structures stacked on the transparent
conductive oxide film from bottom to top, and x is greater than or equal to 2; each unit
cell structure comprises A Si
layers and B SiO2
layers; in each unit
cell structure, n (Si) d (Si) = n (SiO2) d (SiO2), so that the
band gap of the photonic
crystal layer covers the ENZ
wavelength of the transparent conductive
oxide film; and the surface equivalent impedance of the
metal substrate layer and the transparent conductive
oxide film is matched with the relative
surface impedance of the photonic
crystal layer, so that a Tamm state is formed between the interfaces of the transparent conductive
oxide film and the photonic
crystal layer. According to the invention, the bistable effect is realized under multiple incident angles, two polarizations and different wavelengths, the bistable working
wavelength can be moved to an area smaller than the ENZ
wavelength of the material, and the optical bistable state is realized.