Author Affiliations
Abstract
1 School of Electronics Information Engineering, Beihang University, Beijing 100191, China
2 Aerospace Institute of Advanced Material & Processing Technology, Beijing 100074, China
3 School of Information Science and Engineering, Wuhan University of Science and Technology, Wuhan 430081, China
4 Hubei Longzhong Laboratory, Xiangyang 441000, China
In this paper, we propose an ultrabroadband chiral metasurface (CMS) composed of S-shaped resonator structures situated between two twisted subwavelength gratings and dielectric substrate. This innovative structure enables ultrabroadband and high-efficiency linear polarization (LP) conversion, as well as asymmetric transmission (AT) effect in the microwave region. The enhanced interference effect of the Fabry–Perot-like resonance cavity greatly expands the bandwidth and efficiency of LP conversion and AT effect. Through numerical simulations, it has been revealed that the cross-polarization transmission coefficients for normal forward (-z) and backward (+z) incidence exceed 0.8 in the frequency range of 4.13 to 17.34 GHz, accompanied by a polarization conversion ratio of over 99%. Furthermore, our microwave experimental results validate the consistency among simulation, theory, and measurement. Additionally, we elucidate the distinct characteristics of ultrabroadband LP conversion and significant AT effect through analysis of polarization azimuth rotation and ellipticity angles, total transmittance, AT coefficient, and electric field distribution. The proposed CMS structure shows excellent polarization conversion properties via AT effect and has potential applications in areas such as radar, remote sensing, and satellite communication.
chiral metasurface linear polarization conversion asymmetric transmission Fabry–Perot-like resonance electromagnetic interference model Chinese Optics Letters
2023, 21(11): 113602
1 天津大学微电子学院 天津市成像与感知微电子技术重点实验室， 天津 300072
2 天津大学 电气自动化与信息工程学院， 天津 300072
针对可见光通信对硅基光电探测器高响应度的要求，本文利用亚波长金属光栅的异常光学透射现象，提出一种增强与硅基CMOS工艺兼容的金属-半导体-金属光电探测器吸收的方法。采用时域有限差分法，详细分析了光栅周期、光栅高度和狭缝宽度对探测器吸收性能的影响，证明了类法布里-珀罗共振和表面等离子体激元是吸收增强的物理起源。对于波长615 nm的红光通信而言，探测器金属光栅的最佳周期、最佳高度和最佳狭缝宽度分别为580，91，360 nm。与没有亚波长金属光栅结构的探测器相比，本文设计的探测器吸收系数提高了32%。本文研究的MSM探测器结构与CMOS工艺完全兼容，有望在可见光通信芯片中得到实际应用。
可见光通信 光电探测器 亚波长金属光栅 吸收增强 类法布里-珀罗共振 表面等离子体激元 visible light communication photodetector subwavelength metal grating absorption Fabry-Perot-like resonance surface plasmon polariton
