中国光学（中英文）2025，Vol.18Issue(4)：738-747,10.DOI:10.37188/CO.2024-0197
基于金属基底非对称介质超光栅的太赫兹宽带吸收谱增强
Terahertz broadband absorption spectrum enhancement based on asymmetric dielectric meta-grating on a metal substrate
摘要
Abstract
Terahertz molecular fingerprinting is a promising method for label-free detection,particularly for micro or trace amount samples in practical applications.However,the wavelength of terahertz waves is much larger than the size of the molecules to be tested,resulting in a weak interaction between the waves and the matter.To address this challenge,additional structures are needed to enhance the absorption of electromag-netic waves by trace amount samples.In this study,we constructed an inverted asymmetric dielectric grating structure on a metal substrate.By utilizing guided-mode resonance(GMR)and a bound state in the con-tinuum(BIC)effect,the terahertz absorption spectrum of thin film samples was significantly enhanced.The enhanced absorption spectra can be easily obtained by measuring the reflected absorption signal.The samples are coated on the flat back of the inverted dielectric grating,which simplifies the preparation process.For in-stance,when the thickness of an α-lactose film is 0.2 μm,the absorption enhancement factor reaches 236.This study provides a new method for detecting trace analytes in the terahertz band.关键词
太赫兹/指纹谱/吸收增强/超光栅/金属基底Key words
Terahertz/fingerprint spectrum/absorption enhancement/meta-grating/metal substrate分类
信息技术与安全科学引用本文复制引用
王子靖,李向军,严德贤..基于金属基底非对称介质超光栅的太赫兹宽带吸收谱增强[J].中国光学（中英文）,2025,18(4):738-747,10.基金项目
浙江省公益技术研究工业项目(No.LTGN23C180003) （No.LTGN23C180003）
国家重点研发计划(No.2021YFF0600300) （No.2021YFF0600300）
国家自然科学基金资助项目(No.62175223)Supported by Basic Public Welfare Research Project of Zhejiang Province(No.LTGN23C180003) （No.62175223）
National Key R & D Program of China(No.2021YFF0600300) （No.2021YFF0600300）
National Natural Science Foundation of China(No.62175223) （No.62175223）
