Research Of Short-Wavelength Pass Filter

Dichroic beam combiner is used in multicolor spectrometric system including color television, movie, printing and so on, which is filter that makes the red light reflected and green light transmitted. To improve the ability of dichroic beam combiner, the paper based on the fact of combining the condition and technique of now designs and produces the filter of satisfying require, which is ended in 600-640 wave band. Then the monitor wavelengths is 650nm, wave band between 400～510nm is high transmission.First we start from the theory of film optics and systematically analyse film knowledge, then study the reflectance and transmission to analyze film system; Secondly we analyze the ability and parameter of the film we needed by considering the problem of film matching to confirm film. Then making use of the computer simulation to find the best design plan to confirm the actual technological parameters of this filter; In the process of evaporating considering the infection of film layer ability caused by different arts and crafts parameter we adopt corresponding measure in time, for example the procedure control and so on ;We systematically make error analysis of the result of coating, then find the method to minish error.The result of checking filter is that the range of high transmission is 380-510nm and the average transmission achieves above 85%.We require it keep high reflected within range of 550-640nm and the most transmission achieves less than 1%;To more appraise the characteristic of cutoff filter in the transition from the pass band to the stop band, we induct the intervening region offsetting to consider one new appraising parameter which is the offsetting of cutoff wavelength. By measuring every index the production achieves the requirement of design.In this paper the arts and crafts procession of making filter is given by the use of film-plating machine of Balzers BAK 600.