一维亚波长红外偏振光栅全息光刻加工  

Holographic lithography of one-dimensional subwavelength infrared polarization gratings

作　　者：陆天石 邓富元 李星辉 LU Tianshi;DENG Fuyuan;LI Xinghui(Shenzhen International Graduate School,Tsinghua University,Shenzhen 518055,China;Tsinghua-Berkeley Shenzhen Institute,Tsinghua University,Shenzhen 518055,China)

机构地区：[1]清华大学深圳国际研究生院,广东深圳518055 [2]清华-伯克利深圳学院,广东深圳518055

出　　处：《光学精密工程》2024年第21期3147-3156,共10页Optics and Precision Engineering

基　　金：广东省基础与应用基础研究基金资助项目(No.2021B1515120007)。

摘　　要：亚波长光栅作为一种体积小,易于集成,消光比高的偏振选择器件,在遥感探测、材料应力探测和抗散射成像等领域有着丰富的应用前景。本文设计了高消光比,高透过率的一维亚波长光栅偏振选择器件,并实现其高效的加工方式。首先,基于等效介质理论和有限时域差分对光栅进行设计和仿真,设计了一种对全息干涉加工友好的双层金属结构的一维亚波长光栅偏振器件,具有占空比稳定及易于图形转移的优势。之后搭建了全息激光光刻系统,完成800 nm周期的30 mm×30 mm一维光栅的加工,较于传统方法,在加工效率、成本和周期可调节性上具有较大优势。通过刻蚀硅基底和镀金属膜实现了光刻胶图形向金属光栅的转移。制成的光栅对3~15μm的红外光有着超过45%的平均透过率和30 dB的最大消光比。Subwavelength gratings,as compact,easily integrable polarization-selective devices with high extinction ratios,hold significant potential for applications in remote sensing,material stress detection,anti-scattering imaging,and related fields,garnering widespread attention.In this study,we design a one-dimensional subwavelength grating polarization-selective device with high extinction ratios and high transmittance,along with an efficient fabrication method.Utilizing the effective medium theory and finite-difference time-domain simulations,we developed and modeled a one-dimensional subwavelength grating device featuring a double-layer metal structure optimized for holographic interference processing.This design offers robust duty cycle tolerance and facilitates the direct transfer of photoresist patterns.A holographic laser lithography system was constructed to fabricate one-dimensional gratings with dimensions of 30 mm×30 mm and a period of 800 nm.Compared to conventional techniques,this approach demonstrates significant advantages in processing efficiency,cost-effectiveness,and tunable periodicity.The transfer of photoresist patterns to metal gratings was achieved via silicon substrate etching and metal film deposition.The resulting gratings exhibit an average transmittance exceeding 45%and a maximum extinction ratio of 30 dB for infrared wavelengths in the range of 3-15μm.

关 键 词：全息光刻 双层金属光栅 亚波长光栅 偏振选择 

分 类 号：TH74[机械工程—光学工程] TN305.7[机械工程—仪器科学与技术]