Document Retrieval Instruments-Study On Long-Wavelength Pass Filters

Long-Wavelength Pass Filter is an important part of the system of the document retrieval instrument. The paper briefly introduced designed the coating principle both in thin film theory and thin film design theory. Specified to the wavelength between 380nm and 720nmtransmitted, designed and optimized the film, the materials were used as TiO₂ and SiO₂, andprepared by the GX-900A full automatic vacuum coating machine, with the electron beam and the ion assistance system. We tested the spectrum characteristic with UV3100PC spectrophotometer. At last the film system prepared in this way was tested in different environment conditions. The experiment result shows that the specification of this film system can meet the requirement of the design.