Multi-channel Thin Film Filter Design, Fabrication And Testing

There has been more than two hundred years since the vacuum coating technology appeared, especially optical thin film technology has been developed greatly. But the optical filters is facing the new challenges with the development of space technology and is becoming more and more small and integrated. The new designed method for thin film spatial demultiplexer based on Superprism phenomenon of 1D photonic crystal has been introduced. The fabrication and measurement of the facet optical filter with masks and the thin film devices based on Superprism phenomenon are studied and analyzed in this thesis.Firstly the background of the optical film and the measurement is introduced.Chapter two is about the deposition technology of thin films. A new thickness monitoring method is suggested, especially the HR film monitoring method is simulated. With this method the second-class peak nearby the stop band of the deposited film is identical in theory design. The experiment proves this kind of control method can improve and plate the precision of membrane effectively.In Chapter three the four facets (0.8 × 0.8mm) visible light filter with mask method on the satellite's (FY-3) scanning radiometer is studied. The precise size filter is deposited with the mask method successfully, the spectrum characteristic is tested through utilizing the optical fibre spectrometer.In Chapter four the analyses on the characteristic of one-dimension thin film superprism with large beam-separating is presented, including the 1D periodic thin film and thin film Fabry-Perot filter. The group delay and the shift caused by the spatial dispersion were numerically simulated by characteristic matrix method used widely in optical thin film theory. The system used for testing small shift (micrometer) is setup. The results showed that the maximum shift by spatial dispersion is achieved 20 um for thin film with 10 periods and 65 um for F-P filter, which consisted well with the design. When the film stack was added the metal reflector, the reflectivity is increased greatly and the beam-separating caused by the group velocity dispersion of the emergent light is decreased. But through reflecting more times in the film stack the large beam-separating of the emergent light is achieved.Finally summary of project and the suggestion on the work in the future are presented...