用于液晶投影显示的薄膜偏振分束器  

Thin-film polarizing beam splitters used in liquid crystal projection display

作　　者：丁毅[1] 顾培夫[1,2] 孙旭涛[1] 郑臻荣[1] 章岳光[1] 李海峰[1] 

机构地区：[1]浙江大学现代光学仪器国家重点实验室,浙江杭州310027 [2]杭州科汀光学技术有限公司,浙江杭州311100

出　　处：《浙江大学学报（工学版）》2009年第8期1433-1437,共5页Journal of Zhejiang University：Engineering Science

基　　金：浙江省科技计划资助项目(2004C31107);国家创新基金资助项目(C26113300494)

摘　　要：为提高液晶投影机的光能利用率和图像对比度，设计了一种宽角度宽波长的光学薄膜偏振分束器（PBS）．采用多种薄膜材料产生多个Brewster角，通过优化膜层数目和膜层厚度，获得了宽角度宽波长的PBS．以SF57和SF2玻璃作为棱镜材料，采用TiO2、Ta2O5、Al2O3、SiO2作为薄膜材料，基于上述原理采用全自动的Needle设计方法，设计了4种典型膜系，优化后的膜层数目为50-60层，空气中的光束孔径角达到±10．5°，达到的技术指标为：对于P偏振光，在420-460nm和460-680nm波长范围内，积分透射率分别达到88．0％和93．4％；而对于S偏振光，在420-680nm波长范围内，积分透射率为0．095％．该PBS应用于F／2．8的光学系统中，能够显著提高整个系统的性能．In order to improve the energy efficiency and image contrast of liquid crystal display （LCD） projector, a wide-angle and broadband optical thin-film polarizing beam splitter （PBS） was designed. Several thin-film materials was adopted to achieve multi-kinds of Brewster＇s angles. The number and thickness of the films were optimized to obtain the wide-angle and broadband PBS. Using SF57 and SF2 glasses as prism materials, and TiO2, Ta2O5, Al2O3, SiO2 as film materials, four typical PBS multi-layer designs were given based on the above principle and the automatic Needle design method. The layer number of the optimized thin-film is 50-60, and the incident angle in air for the PBS reaches ±10. 5°. The measured re- suits showed that the integrated transmittance of P-polarization was 88.0~ and 93.4% respectively at wavelength of 420--460 nm and 460--680 nm as well as that of S-polarization was 0. 095 % at wavelength of 420--680 nm. The PBS can be applied to F/2.8 optical systems to improve their performance obviously.

关 键 词：液晶投影机 光学薄膜 偏振分束器 宽角度PBS1宽波长PBS 

分 类 号：O484[理学—固体物理]