Tunable multichannel optical absorber based on coupling effects of optical Tamm states in metal-photonic crystal heterostructure-metal structure

Abstract A tunable multichannel optical absorber based on optical Tamm states (OTSs) in metal-photonic crystal heterostructure-metal (M-PCH-M) structure is proposed. OTSs can be excited at the interfaces of the optical absorber and strong coupling effects occur between them. The proposed optical absorber is theoretically analyzed and numerically investigated by using the transfer matrix method (TMM). The results show that the metal film thicknesses of the optical absorber have a certain tolerance and high absorptivity can be maintained when the thicknesses of metal films vary at a range. The wavelengths of absorption peaks can be designed by changing the top layers thicknesses and the absorptivity of absorption peaks will be hardly influenced. Moreover, by changing the angle of incidence, the absorption peaks can be tuned and maintain high absorptivity at a range for both TE and TM modes. The optical absorber in this paper will have potential applications in solar cells, sensors, thermal radiation and narrowband wave filters.