1.06μm / LWIR dual band antireflection coatings were designed and prepared onto ZnSe substrate. Resonance field effects were investigated at the designing stage to improve laser damage threshold of the coatings, and films were prepared onto substrates with different surface quality and properties of the deposited films were investigated. The packing density and mechanical properties of ZnS films were improved by experiment analysis of ZnS prepared by IAD and optimization of the parameters of this technique. The technique properties of the materials dispersive absorption data based on optimized parameters were stable, and the optical property of the deposited films was improved. Films with transmittance of above 96.5% in the 7.7~10.5 μm region and 94% at 1.064 μm and laser damage threshold above 85MW/cm2 were prepared with such parameters, and the dual band AR coatings passed environmental tests specified by MIL-C-675C. The coated ZnSe windows meet with the demands of electro-optical systems, in which laser and IR works in common aperture, serviced in battlefield environment.
In this work, the improvement of IAD technique to packing density of YF3 films with low absorption over the broadest spectral range, has been investigated. YF3 films were prepared by e-beam evaporation of pure YF3 with Ion Assisted Deposition, DI=0A, 0.8A, 1.0A, 1.2A, (DI is the drive current during deposition of the YF3 films). The packing density of films is inspected generally by water and salt water soak test. The optical properties of all samples were measured and analyzed before and after soak test. The calculation of optical constants for different samples is based on spectrum cures. By comparing the varieties of refractive index and extinction coefficient of different samples, we have found the ideal process parameters of deposition for YF3 film. Then, the 3~5 μm and/or 8-11.5 μm infrared antireflective coatings have been fabricated by using the process parameters of deposition YF3. All samples passed MIL-F-48616 environmental tests and meet with the application demands of military optoelectric equipment.
In this work, electrochromic tungsten oxide thin films doped with terbium were deposited by radio frequency magnetron sputtering deposition. The samples were analyzed with scanning electron microscopy (SEM), atomic force microscopy (AFM) and x-ray diffraction (XRD). The films were amorphous and the thickness of the films is about 250 nm. From the result of AFM, the WO3 films doped with terbium are porous and the sample doped with 1.95% Tb has more porosities than undoped sample. Cyclic voltammetry experiments were performed to investigate the influence of terbium content on the electrochromic performance of the films. When the terbium content is equal to 1.95%, the cell capacity owns the best electrochromic capability. Measurement of optical transmission measurement for W-Tb-O thin films was carried out by a double-beam UV-VIS-NIR spectrophotometer with a wavelength range from 380 nm to 900 nm. In the different wavelength ranges, the films have different transmittance changes for the bleaching and colored state.