A Tunable Holographic Grating with Red-Sensitive Photopolymer and Polymer-Dispersed Liquid Crystal

The photographic plate was fabricated from red- sensitive photopolymer on the ITO glass for the first time. The holographic grids were made by double path-interference using semiconductor laser (lambda = 635 nm) as light source. The holographic grids and polymer-dispersed liquid crystal (PDLC) were pressed together to get a new optical grating with a grating constant of 521.6 nm. We measured its e-o parameters including the response time and the diffraction efficiency etc. It is shown that the structure is provided with a fine line and flexible electric field modulability to the light of diffraction. The obvious grating diffraction effect was observed when the driving voltage was larger than 10 v. It was also tested that the response time was 30 ms when voltage was 20 v.