透射式金属光栅耦合SPR传感器

Transmissive Metal Grating Coupled SPR Sensor

用磁控溅射技术在双面抛光的蓝宝石衬底上沉积了20 nm Ti和100 nm Au的金属薄膜,通过标准光刻工艺制备出1.6和2.0μm两种周期结构的一维光栅表面等离子体共振(SPR)传感器。用时域有限差分算法(FDTD)模拟仿真并结合实验测试的透射光谱,研究分析了不同周期结构的金属薄膜光栅型SPR传感器的特性。基于金属光栅耦合,利用表面等离子体激元(SPP)的局域特性和光栅的选频特性,实现了SPR传感器的信号增强和滤波功能。研究结果表明,利用金属薄膜光栅表面介质的变化引起的光栅透射光谱中激发表面等离子体共振峰的位置变化,可以获得被测物体的物理、生物和化学等相关特征信息。

The compound metal films with 20 nm Ti and 100 nm Au were deposited using magnetron sputtering technology on double-sided polished sapphire substrates and one dimension grating surface plasmon resonance （SPR） sensors with 1.6 um and 2.0 um periodic structures were fabricated by standard lithography technique. By making use of simulating with finite-difference time-domain （FDTD） and testing the transmission spectra, the characteristics of the metal film grating SPR sensor with different period structures were analyzed and investigated. The signal enhancement and filtering function of the sensors were achieved by use of the locality of surface plasmon polaritons （SPP） and the selectivity of grating on the basis of metal grating coupled. The results suggest that the characteristic information of physics, biological and chemical of the object are tested by means of peak position change of the SPR transmission spectra when the medium in the metal film grating SPR sensor is changed.