Polarization-dependent and angle-insensitive absorber with hyperbolic material

Abstract

A polarization-dependent and angle-insensitive absorber based on surface phonon polaritons (SPhPs) is proposed based on a sandwiched layer structure that consists of a patterned α - M o O 3 layer, a dielectric layer, and a gold layer. The absorption remains larger than 95% for TE incidence wave with incident angles from 0° to 30° in the wavelength range from 13.7 to 18.3 µm, which is a broadband absorber. At the same time, the absorption remains larger than 95% for TM incidence wave with incident angles from 0° to 60° in the wavelength range from 11.52 to 11.66 µm, which is a narrowband absorber. It is interesting that the absorber can also be used to fabricate the ideal filter of transverse electric (TE) wave in the wavelength range from 11.52 to 11.66 µm and an ideal filter of transverse magnetic (TM) wave from 15.03 to 18.37 µm. Moreover, one can combine an ideal filter of polarization and a perfect absorber into one single device. The proposed absorber shows promising performance, which has potential applications in sensing, imaging, and detection.

A polarization-dependent perfect absorber with high Q-factors enabled by Tamm phonon polaritons in hyperbolic materials

“…For example, Sui et al demonstrated an a-MoO 3 metasurface absorber based on surface phonon polaritons with polarization-dependent and angle-insensitive absorption properties in the mid-infrared band. 45 Currently, the understanding of the light-matter interaction in a-MoO 3 is still in its nascent stages, and there is limited research on a-MoO 3 based electromagnetic absorbers, particularly those exhibiting polarization-dependent perfect absorption. However, the exploration of such absorbers holds immense importance for various applications like photodetectors, optical communication, and technical inspection.…”

Large spatial shifts of reflected light beam off biaxial hyperbolic materials

“…On the other hand, α-molybdenum trioxide (α-MoO 3 ) exhibits phonondriven NBHM behaviour in the long-wavelength mid-infrared range, making it a promising candidate for creating optical components with superior efficiency. [30,31] α-MoO 3 , a type of van der Waals crystal with orthorhombic unit cells, shows a biaxial hyperbolic anisotropy in the mid-infrared part of the electromagnetic spectrum. [32,33] The inherent anisotropy of α-MoO 3 , arising from its distinctive crystalline structure, results in natural in-plane hyperbolic characteristics that stem from the interplay between the lattice modes and three crystal directions that are orthogonal to each other.…”

Volume-Confined Hyperbolic Polaritons and Surface-Confined Hyperbolic Polaritons in Ultrathin Hyperbolic Sheets and Their Identification

“…Hyperbolic materials are extreme anisotropic materials, whose permittivity tensor has diagonal elements of not all the same sign. [1][2][3][4][5][6] They can support high-wavevector propagating waves and possess distinctive properties different from that of conventional materials, and thus they have attracted significant attention over the past few years. [7][8][9][10][11][12][13] So far, hyperbolic polaritons (HPs) have been discovered in natural hyperbolic materials, such as hexagonal boron nitride (hBN) and alpha-phase molybdenum trioxide (α-MoO 3 ).…”