| For infrared detector and chemical lasers,2-6μm infrared band is one of the most widely used wavelength regions. Coating materials used in this band are mainly flourides,sulfides and selenides. Oxides have excellent mechanical properties and environmental stability, and have already been successfully used in visible and near-infrared region, to fabricate high-performance coatings. But articles about oxides applied to mid-infrared are very few. It is meaningful to begin the work to study mid-infrared properties of oxide thin films, which may broaden the applications of oxides and solve the problem that commonly used infrared materials are neither stable nor adhesive.In the present paper, ion beam sputtering deposition is employed to prepare oxide thin films, and the optical properties, microstructure, stress and environmental stability about these films are studied. Mid-infrared high reflectors are also prepared using oxides as high and low refractive index materials. Main contents are as following: 1.Different kinds of oxide thin films are prepared using IBSD technology, and their properties including spectrum, optical constants, microstructure, environmental stability are studied. 2.Defects of both dispersion Model fitting method and Kramers-Kronig transform method are analyzed, and we develop a method to calculate the optical constants of films in the mid-infrared which combine these two methods. 3.2.7μm and 3.8μm high reflectors are designed and fabricated, reflection spectra are measured via Fourier-transform infrared spectroscopy. Section topography is detected by Scanning electron microscope. The annealing properties are also studied. 4.to explain the distortion of reflection spectrum of these high reflectors, sectiontopography image processing and spectrum fitting method are used to analyze the thickness changing in different layer. The results are nearly identical. Key Words: thin films, ion beam sputtering, mid-infrared, water absorption, optical... |
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