基于PDMS自组装褶皱结构的近红外亚波长金属偏振光栅设计分析

Design and Analysis Sub-wavelength Metallic Wire-grid Polarizer for Near-infrared Based on Self-assembly Wrinkle of PDMS

提出一种以聚二甲基硅氧烷(PDMS)为基底,结合氧气等离子体氧化处理在PDMS表面生成类二氧化硅刚性层,通过聚对苯二甲酸乙二醇酯(PET)柔性薄膜谐调应力在柔性衬底/刚性薄膜的表面自组装形成有序结构的方法。并制备了周期450 nm、占空0.5、高度100 nm的有序的亚波长正弦光栅结构,以此为基底设计了可用于近红外的金属偏振光栅。结合不同的金属纳米薄膜沉积方法,以严格耦合波理论为分析基础,分析了这三种光栅在近红外波段的偏振性能。分析结果表明,金属层的结构对光栅的偏振性能影响很大,三种结构各有优劣。这种基于自组装结构的加工方法有望解决亚波长金属光栅生产周期长、生产成本高的问题。

A method for fabricate self-assembly structures on the substrate /stiff film is proposed,which is set the polydimethylsiloxane（ PDMS） as substrate and treat it with oxygen plasma to generate Si O2-like layer,the（ polyethylene glycol terephthalate） PET is used for stress coordination. The sinusoidal grating with period 450 nm,duty cycle 0. 5,amplitude 100 nm was formed and the sub-wavelength metallic wire-grid polarizer was designed based on such grating. Combining with different methods of metal evaporation,the polarization properties of three different metallic wire-grid polarizers are analysized in near-infrared use Rigorous Coupled Wave Analysis（ RCWA）,the results show that the structure of the metal wire have great impact on polarization properties and each grating with different structures has its own merits. The processing method based on the self-assembly structure is expected to be solve long production cycle and high-cost for fabricate the sub-wavelength metal grating. In the future,such metallic wire-grid polarizers may used in liquid crystal devices,infrared imaging system,optical communication and other fields.