Non-polarized and ultra-narrow band filter in MIR based on multilayer metasurface

Wentian Chu; Xuepeng Xu; Chunfeng Cai; Huizhen Wu; Gang Bi

doi:10.1016/j.heliyon.2023.e21303

Non-polarized and ultra-narrow band filter in MIR based on multilayer metasurface

Heliyon. 2023 Oct 23;9(11):e21303. doi: 10.1016/j.heliyon.2023.e21303. eCollection 2023 Nov.

Authors

Wentian Chu^{1

2}, Xuepeng Xu^{1

2}, Chunfeng Cai^{3

4}, Huizhen Wu⁵, Gang Bi¹

Affiliations

¹ School of Information and Electrical Engineering, Hangzhou City University, No. 48, Huzhou Street, Hangzhou, 310015, China.
² College of Information Science and Electronic Engineering, Zhejiang University, No. 38, Zheda Road, Hangzhou, 310027, China.
³ Fundation Science Education Center, Hangzhou City University, No. 48, Huzhou Street, Hangzhou, 310015, China.
⁴ State Key Lab of Silicon Materials, Zhejiang University, No. 38, Zheda Road, Hangzhou, 310027, China.
⁵ Department of Physics, Zhejiang University, No. 38, Zheda Road, Hangzhou, 310027, China.

Abstract

We propose an ultra narrow-band filter in the mid infrared region (MIR) using artificial metamaterials (AMM), which is suitable for the design of on-chip photonic spectrometers. 2-D rectangular holes with a cross-like layerout are adopted to enhance the filter's efficiency and precision. Considering the penetration depth of electromagnetic (EM) waves in the metal film, we opt for multi-layer films composed of metal layers and dielectric layers, instead of a single metal layer, to improve the structure's performance in the MIR. This multilayer configuration significantly enhances the efficiency and precision of the AMM structures in the MIR. The transmission peak, with a full width at half maximum (FWHM) of 30 nm, can be achieved and tuned in the wavelength range from 3.0 μm to 10.0 μm by changing the periods of the unit cell (enlarging the unit cell from 3.0 to 10.0 μm). The proposed AMM structures, with tunable narrow band transmittance in MIR, exhibit promising potential in the fabrication of narrow band photonic detectors and on-chip spectrometers.

Keywords: Artificial metamaterials; Mid infrared region; Ultra-narrow band filter.