TiN-based Tamm-FP Coupling Infrared Perfect Absorber with a Narrowed Linewidth

In this paper, an optical device with selectively perfect absorption in the infrared range is proposed. A transition metal nitride-TiN, which is considered as a potential substitute of plasmon material for traditional noble metal, is used to replace the noble metal used in conventional devices. In virtue of the Tamm-FP coupling mode generated in such a structure, the simulation results can obtain a narrowed absorbance band. By changing the thickness of the spacer in the cavity, the peak of the absorption spectrum varies continuously and shifts along with the Distributed Bragg Reflector (DBR) stopband. The filter based on TiN provides the possibility to achieve an excellent filtering effect in the mid-infrared range. It has potential application value and prospects in many fields such as spectroscopy, remote sensing, medical treatment, environmental protection, and the military.