Fabrication Of Filter Film Using In Polarized Light Guide Prism System

Aiming at the special requirements for filter film of the optic prismatic system, basing on the design theory, and choosing the appreciate film materials, a high reflectance film and a splitter film are designed respectively. The films can satisfy with the optical requirement perfectly, when the incidence light is P polarized at the25angle in the range of the visible wavelengths (450nm-650nm). During the preparation process, the optical film absorption is solved by continually optimizing the process parameters, such as temperature, rate of evaporation and ion assisted deposition parameters, etc. Meanwhile, the error produced in the process of preparation is analyzed and revised through several repeated tests and researches, so that the control precision of layer thickness is improved. Finally the high-reflective film with average reflectance over99.5%in the450～500nm band and the beam splitting film with transmittance and reflectance ratio of1:1and1:2in the450-650nm band are prepared respectively, most of all, both errors of the film are less than1%. After the spectrum testing and analyzing, the spectrum curve shows that all the parameters meet the basic requirements for usage.