物理学报Issue(14)：1-6,6.DOI:10.7498/aps.64.147302
复合金属光栅模式分离与高性能气体传感器应用∗
Split mo des of comp osite metal grating and its application for high p erformance gas sensor
摘要
Abstract
To achieve the surface plasmon resonance (SPR) mode splitting in infrared wavelength band, and to improve the figure-of-merit (FOM) of grating based SPR sensor, in this article we present a new composite grating structure, which consists of double metal gratings, and study the gas sensing performance. Split modes of SPR in composite metal grating are observed by using the finite difference time domain method. The original structure symmetry is broken and changed with increasing relative displacement between the double gratings, as a result, the resonant modes move to opposite directions. Calculated electric field distribution of the two separate resonant modes displays two different degrees of coupling effect between the double gratings. When the relative displacement is further increased till the double gratings are connected to form a new symmetrical single grating, the separate resonant modes will merge into another single resonant mode. If the refractive index of analyte (na) is in a range 1.01 6 na 6 1.05 and the relative displacement of double gratings is zero, the wavelength sensitivity based on composite metal grating gas sensor reaches 1207.5 nm/RIU (per refractive index of unit) and the FOM is obtained to be 1290.7, while the relative displacement of the double gratings is 100 nm, for the double split modes the wavelength sensitivities are 1205.0 nm/RIU and 1210.0 nm/RIU, respectively, and the corresponding FOMs are 1295.4 and 762.3. Therefore, the high FOM of the composite grating based on SPR sensor possesses great potential applications in biochemical sensing.关键词
表面等离子体共振/复合光栅/模式分裂/气体传感器Key words
surface plasmon resonance/composite grating/mode splitting/gas sensor引用本文复制引用
孙小亮,陈长虹,孟德佳,冯士高,于洪浩..复合金属光栅模式分离与高性能气体传感器应用∗[J].物理学报,2015,(14):1-6,6.基金项目
国家自然科学基金(批准号:61176064)资助的课题.@@@@* Project supported by the National Natural Science Foundation of China (Grant No.61176064) （批准号:61176064）
