可见光宽入射角度金属偏振分束光栅的消光比特性研究  

Polarization Extinction Ratio Characteristics of Visible Wide-angleMetal Polarization Beam Splitting Grating

作　　者：孙国斌[1] 张锦[1] 季雪淞 胡驰 蒋世磊[1] 刘严严 SUN Guobin;ZHANG Jin;JI Xuesong;HU Chi;JIANG Shilei;LIU Yanyan(School of Optoelectronic Engineering,Xi'an Technological University,Xi'an 710021,China;National Key Laboratory of Electromagnetic Space Security,Tianjin 300308,China)

机构地区：[1]西安工业大学光电工程学院,西安710021 [2]电磁空间安全全国重点实验室,天津300308

出　　处：《光子学报》2023年第12期89-98,共10页Acta Photonica Sinica

基　　金：陕西省教育厅重点实验室科研计划(No.18JS053);电磁空间安全全国重点实验室基金。

摘　　要：设计出一种工作在可见光波段宽入射角度范围具有高消光比的金属偏振分束光栅。采用等效介质理论对金属偏振分束光栅原理进行定性分析,利用严格耦合波理论和时域有限差分法对金属Al光栅进行数值仿真并详细分析了结构参数中周期、高度以及光波长和入射角度等参数对偏振特性的影响。结果表明:当Al光栅占空比为0.5,周期为0.15μm,光栅脊高度为0.15μm时,在0.4~0.7μm波段和45°±10°入射角范围内,该金属偏振光栅对TM波高透射,对TE波高反射,光栅透射消光比平均35 dB,反射消光比平均12 dB,最后对制作的金属偏振光栅进行消光比测量,验证了设计结果的正确性。该研究结果对设计和制备高衍射效率、高消光比、宽波段宽入射角度范围的偏振分束器具有较好的实践指导价值。The polarization beam splitter is one of the essential devices in a polarized optics system,which can change the polarization characteristics of light quickly and effectively.Conventional polarizing beam splitters are expensive,bulky,structurally unstable,and sensitive to the angle of incidence,thus limiting their application in optical systems.In recent years,with the realization of micro-nanostructures on the surface of optical elements,special functions such as polarization,anti-reflection,narrow-band filtering,and diffraction enhancement of optoelectronic devices can be achieved by fabricating micro-nano-grating structures on the surface of the device's substrate material.However,most of these structures working wavelength range,incident angle tolerance,and extinction ratio are essential factors restricting their wide development and application.Therefore,to obtain a polarization beam splitter with a simple structure,easy processing,and suitable for the polarization beam splitting requirement of high extinction ratio at wide incidence angles for AR display components,this paper designs a metal polarization beam splitter grating with high extinction ratio to work in a wide range of incidence angles of visible light bands to address this problem.The metal polarization beam splitting grating principle is qualitatively analyzed using equivalent medium theory,and then effects of the period,height,beam wavelength,and incident angle on the polarization characteristics of the Al grating are numerically simulated by using rigorous coupled wave analysis theory and finite difference time domain method.The results show that when the Al grating duty cycle ratio is 1∶1,the period is 0.15μm,the ridge height is 0.15μm,in the 0.40~0.70μm band and 45°±10°incident angle range,the metal polarization grating has a high transmission to TM wave and high reflection to TE wave at the 0 order diffraction order,the transmission extinction ratio is 35 dB on average,the reflection extinction ratio is 12 dB on average.Finally,the

关 键 词：亚波长金属光栅 偏振分束 等效介质理论 严格耦合波理论 时域有限差分法 

分 类 号：O436.3[机械工程—光学工程]