内凹形针尖的拉曼散射增强特性

Raman Scattering Enhancement Characteristic of Concave Tip

利用基于时域有限差分法的FDTD Solutions软件建立了镀银膜内凹形钨针尖-玻璃基底仿真模型,在相同条件下对镀金膜内凹形钨针尖-玻璃基底、内凹形钨针尖-玻璃基底模型的近场电场分布进行数值计算,验证了所设计的模型在拉曼散射增强方面的有效性。研究结果表明:在镀银膜内凹型钨针尖-玻璃基底情况下,该结构可产生最大的拉曼增强因子,为105量级。利用中国计量科学研究院的针尖制备装置制备了优化参数的针尖实物,并利用实验室中的TERS测量装置实现了SWCNTs的TERS信号测量,验证了所设计的针尖在拉曼信号测量方面的有效性。

The FDTD Solutions software which is based on the finite-difference time-domain method was used to establish a simulation model of the Ag-coated concave W tip and glass substrate.In the same conditions,within the Au-coated concave W tip-glass substrates,inner concave W tip-glass substrate models of near-field electric field numerical calculation,the design verified the effectiveness of the model in terms of enhanced Raman scattering.The results show that the structure can produce the largest Raman enhancement factor of the order of 105 in the case of an Ag-coated recessed W tip-glass substrate.The tip preparation device of the National Institute of Metrology of China was used to prepare the actual tip with optimized parameters,and the TERS measurement device in the laboratory was used to measure the TERS signal of SWCNTs,experiment rusults verify the effectiveness of the designed tip in Raman signal measurement.