根据杂化表面等离激元的产生机理和传统杂化表面等离激元的波导结构,提出了一种多层波导布拉格光栅结构。该结构采用SiO2和NaF两种低折射率介质作为芯层,形成了多层波导布拉格光栅的结构。在1550 nm通信波长下,围绕光波的传输距离和模场限制能力对光栅的结构进行了研究及优化。在此基础上,进一步分析了光栅周期数与光波反射率之间的关系。仿真结果表明:该光栅的传输距离和有效模场面积分别为178.12 μm和0.203 μm 2;该结构不仅可以降低金属表面对光场限制所形成的损耗,而且表现出了较强的模场限制能力;当周期数为60时,光波的反射率能够达到71.9%,该结构具有良好的滤波特性。

According to the excitation mechanism of hybrid surface plasmon polaritons and the waveguide structure of traditional hybrid surface plasmon polaritons, a multilayer waveguide Bragg grating is proposed. Two low refractive index materials, SiO₂ and NaF, are used as the core layer in the structure. At the communication wavelength of 1550 nm, the structure of the grating is studied and optimized for the transmission distance and the mode field limitation ability of the light wave. And the relationship between the grating period number and the reflectivity of light wave is further analyzed. Simulation results show that the transmission distance and the effective mode field area of the Bragg grating are 178.12 μm and 0.203 μm ², respectively. The structure not only reduces the loss due to the light field limitation at the metal surface, but also reflects relatively strong mode field limitation. The reflectance can reach 71.9% when the grating period number is 60, and the structure has a good filtering characteristic.