基于银纳米颗粒的HCPCFSERS传感系统优化设计

银纳米颗粒与光子晶体光纤、表面增强拉曼散射效应结合而成的PCF SERS传感器得到了科研界的广泛关注.而PCF结构、SERS基底的性能是传感器的重要影响因素.为了进一步提高SERS PCF传感器的性能,通过研究对比PCF和SERS基底结构参数对传感性能的影响,设计出适用于PCF SERS传感的空芯PCF以及SERS基底的结构参数.通过数值计算,设计的空芯PCF空气填充率为56.30%,当激发光波长785 nm时存在光子带隙,并能够实现单模传输.而半径为38 nm的银纳米球在间距为0.7 nm时能够产生最大的SERS增强因子.研究证明,设计的空芯PCF在785 nm输入波长下既能够基模传输激发光,又能够为SERS提供理想的活性面积,而且银纳米颗粒的形状、尺寸、间距对SERS性能影响严重,而且与入射波长有很强的依赖关系.

Optimization on HCPCF SERS sensor based on silver nanoparticles

Silver nanoparticles, combine with PCF and surface enhanced Raman scattering(SERS), form SERS PCF sensor, and has been applied widely. But in practical, the PCF structure and the performance of SERS substrate have fatal influence on sensor. To exert sensor's practical applications fully, the influence of HCPCF(hollow core PCF) and silver nanoparticles substrate structure on sensor were researched and analyzed, then the novel HCPCF and silver nano-substrate were designed to suit for SERS PCF sensor. Through numerical calculation, the air filling fraction of designed HCPCF is 56.30%. When incident wavelength is 785 nm, there is the photonic bandgap in HCPCF, and HCPCF can transmit fundamental mode, so it suits SERS sensor very well. And silver nanosphere whose radius is 38 nm, and separation distance is 0.7 nm has maximum SERS enhancement factor. The results show that when incident wavelength is 785 nm, the designed HCPCF can supply perfect active area, and the shape, size and separation distance of silver nanoparticles have serious influence on SERS performance, moreover SERS performance rely on incident wavelength seriously.