Optical Resonators Based on Vanadium Dioxide Gradient Films

The article presents experimental results of the synthesis and study of thin films of polycrystalline vanadium dioxide (VO2), as well as multilayer optoresonance structures based on them. The role of the influence of thermal annealing on the structural, electrical and optical properties of VO2 films is shown. Based on these films, photonic crystal heterostructures were fabricated, in which excitation of optical resonance modes of the Fabry–Perot type is observed. A study of the optical transmission of such a structure showed that the spectral position of the Fabry–Perot mode can be controlled by varying the thickness of the VO2 gradient optical layer. It is shown that the first-order semiconductor-metal phase transition, which occurs in VO2 films and is accompanied by a change in their electrical conductivity by 3–5 orders of magnitude, leads to a change in the optical parameters of both the films themselves and multilayer optoresonance structures.