摘要
红外光谱技术因分子吸收截面较小限制了其灵敏度,采用光学性质相似且价格更低的银阵列替代金阵列,在节约成本的同时,利用表面增强红外吸收效应,以提高微量分析物的检测灵敏度。分别设计了微米尺度的中空十字形与六边形天线阵列结构,使用时域有限差分算法进行数值仿真,研究了天线尺寸对超表面光学性能的影响。利用紫外曝光技术,以银作为沉积金属,实现低成本、大尺寸天线阵列的制备。利用傅里叶红外光谱仪测量超表面基底,在400~800 cm^(-1)的中红外波段实现了表面增强吸收,十字形天线与六边形天线结构的消光系数最高分别可达20%与24.5%。为了评估超表面的传感性能,分别在硅基底和六边形结构的超表面基底上涂覆聚甲基丙烯酸甲酯,六边形天线结构在483.14 cm^(-1)处实现了2.85倍的增强吸收,增强因子为1995。
Infrared spectroscopy is widely studied and applied due to its label-free and accurate molecular identification capabilities.However,the small absorption cross-section of the molecule limits its sensitivity.To overcome this problem,the surface-enhanced absorption effect of metal nanoantennas is used to increase the sensitivity when detecting trace target molecules.In the design optimization of metal nanoantenna arrays,silver(Ag)is often used as an alternative to gold(Au)due to its similar properties and lower price.Although much progress has been made in the study of antenna structures,these structures are generally smaller in size,generally less than 100 nm.Relying on advanced technology,the preparation cost is expensive.In this paper,Ag and ultraviolet exposure techniques are used to realize low-cost,largearea metasurface design.First,to study the impact of nanorod size and guide experiments,hollow cross-shaped antenna arrays and hexagonal antenna arrays metasurface are simulated with the help of FDTD software.The simulation results show that the hollow cross-shaped nanoantennas has an extinction peak at 547.7 cm^(-1),and its extinction coefficient is 64.8%.The extinction coefficient of the hexagonal nanoantennas at 448.3 cm^(-1) is 85.5%.Compared with hollow cross-shaped nanoantennas,hexagonal nanoantennas have a redshift in resonant wavelength and a larger extinction coefficient.The parameters of length and width of the hollow cross-shaped and hexagonal antennas are swept separately.For hollow cross-shaped nanoantennas,with the increase of length,the formant is significantly redshifted,and with the increase of width,the formant is slightly blue-shifted.For hexagonal nanoantennas,with the increase of length,the formant is significantly redshifted,and with the increase of width,the formant is slightly redshifted.The influence of length on the position of the formant is much greater than the effect of width.The electric field enhancement of the two antenna structures at 547.7 cm^(-1) and 448.3 cm^(-1) is 576 and
作者
朱恒亮
宋芳
张馨予
郑传涛
王一丁
ZHU Hengliang;SONG Fang;ZHANG Xinyu;ZHENG Chuantao;WANG Yiding(State Key Laboratory of Integrated Optoelectronics,Jilin University Region,College of Electronic Science and Engineering,Jilin University,Changchun 130012,China;Jilin Provincial Engineering Research Center of Infrared Gas Sensing Technique,Changchun 130012,China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2023年第10期21-29,共9页
Acta Photonica Sinica
基金
国家自然科学基金(Nos.62105118,62175087,62235016,61960206004)
吉林省科技发展计划(Nos.20200401059GX,20230201054GX)
吉林省教育厅科技发展规划项目(No.JJKH20211088KJ)
长春市重点研发项目(No.21ZGN24)。
关键词
红外光谱
表面等离激元
表面增强红外
天线阵列
超表面
Infrared spectroscopy
Surface plasmons
Surface enhanced infrared
Antenna arrays
Metasurface
