Research On Near-Infrared Narrow-Band Filters With Wide Rejection Band

In order to meet the special requirements for filter coating of the space optical communication system, Combining the basic theory of thin film, research and analysis film system, preparation technology and related testing technology of near infrared narrow-band filter. Emphatically solved the problem of high cut-off design at the band of near infrared, drift of center wavelength and the improvement of center wavelength transmittance.In the aspect of design, through analyzing the characteristics of the coating materials, using TFC film system design software to optimize the band of wide cut-off area. In the aspect of preparation. Thin film was prepared through electron beam evaporation method and ion-assisted deposition technique, and the thickness of the filter was controlled using crystal-controlled and light control monitoring methods at the same time. Solving the artificial control and the problem of control error which caused by the equipment By continually optimizing technical parameters, the average transmittance of the filter is lower than0.3%at the band of800～1530nm and1600～1800nm, the transmittance at1565nm is higher than92%and the full-width at half maximum of the filter is18nm, and the technical requirements of the optical system are satisfied.