Enhanced Bolometric Detection of THz Signals by a Resonant Structure for Inclined Radiation Incidence

Abstract

In this work, we consider the possibility of enhancing terahertz bolometric detection efficiency using resonant structures in the case of an inclined incidence of radiation. The structures are made of a sequence of doped and undoped semiconductors, including epsilon-near-zero areas. Undoped regions act as electromagnetic resonators, thus ensuring resonant signal penetration through the opaque (doped) regions of the structure. A set of epsilon-near-zero areas can ensure substantial enhancements to the electric field in the material. In the doped regions, absorption occurs. The structure described above can provide efficient resonant energy absorption for a wide range of angles of incidence. The numerical calculations based on the solution of the Helmholtz equation have shown that the studied resonant structures ensure the absorption of up to 50% of the incident radiation energy for a 60-degree incidence.