Study Of Mechanical Angle Affect On The Liquid Crystal Filter

Optical filter is one of the important parts of the modern optical device, which is widely used in all kinds of optical systems, especially in optical measurement, spectral analysis and optical communication technology. At present, various types of optical filters have been developed, such as liquid crystal Fabry-Perot filter, liquid crystal birefringent optical filters, diffraction grating filter. The tunable filter on the development history and research status has done a brief overview, and by comparing the characteristics of several typical filters to confirm the research topics at the focus to liquid crystal birefringent filter.Birefringence liquid crystal filter is the use of nematic liquid crystal cell as a variable phase retarder to build a Lyot-type and Solc-type filter, and they are the two basic types of birefringent filter.In this paper, the principle and application of optical filters are first introduced, and the optics properties of liquid crystal and polarized light interferent theory as well as the structure principle of birefringence liquid crystal filter are analyzed in this paper. The basic principle of Lyot and Solc type liquid crystal filter is described in detail by using polarized light interference and Jones matrix calculation method, and write the corresponding computer simulation program to calculate the transmission of the birefringent filter. The structure of the single stage and multistage Lyot and Solc liquid crystal filter are designed by using the Jones matrix method to calculate and simulate, and simulated by using MATLAB software. By comparing the transmission curves under different construction, the influence on the full width at half maximum and the free spectral range of the liquid crystal filter is analyzed.Secondly, the mechanical deflection angle device is designed by using worm gear and ball guide bar drive mechanism. The spectral transmittance experimental test system is set up on the basis of Ultra UV-6000 series spectrophotometer. The single stage Lyot and multistage Solc folding liquid crystal filter spectral are tested under the mechanical deflection angle device, the test results are given and analyzed. In order to improve the spectral transmittance of the filter and depress the side lobe, a new liquid crystal filter is proposed,which combine the Solc with Lyot,and was proved by experiment.Finally, the whole research work is summarized, and some suggestions are put forward for the further improvement of liquid crystal filter.