Far-infrared anisotropic optical properties of Si3N4 microsphere arrays based on black phosphorus-like structures

• Published in: Applied physics. B, Lasers and optics Vol. 128; no. 8
• Main Authors: Han, Fangwei, Yu, Borong, Zhao, Chengxiang
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.08.2022; Springer Nature B.V
• Subjects: Absorptivity; Anisotropy; Applied physics; Arrays; Electric fields; Engineering; Far infrared radiation; Finite difference time domain method; Lasers; Microspheres; Optical Devices; Optical properties; Optics; Parameters; Phosphorus; Photonics; Physical Chemistry; Physics; Physics and Astronomy; Quantum Optics; Regular Paper; Silicon nitride; Substrates
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-022-07848-1

Optical properties of S i 3 N 4 microsphere arrays based on black phosphorus-like structure are presented in far-infrared regime 8–15 um. Transmittivity and absorptivity along armchair and zigzag direction of S i 3 N 4 microsphere arrays are simulated by finite difference time domain method. In the simulations, geometric parameters such as the distance of two microspheres, the height of the microspheres from the substrate are used to create a black phosphorus-like structure and produce anisotropic optical properties. Then the optical transmittivity and absorptivity as a function of wavelength are calculated for various geometric parameters. When exposed to the radiation field with two kinds of polarizations, the S i 3 N 4 microsphere array based on the black phosphorus-like structure exhibits pronounced optical anisotropy. Specifically, the optical transmittivity (absorptivity) for the polarization along armchair direction is smaller (greater) than that along zigzag direction. These anisotropic optical properties are due to different local electric field distribution. Our research provides a way to produce materials with anisotropic optical properties. We believe that results obtained from this study can provide a guidance for novel artificial anisotropic optical devices.