| As a new kind of technique for making optical coatings, Low Voltage Reactive Ion Plating ( LVRIP ) produces low temperature plasma in vaporizing charm through low voltage, low pressure arc discharge of material vapor and reactive gases, using the very thin electric field naturally generated on the surface of substrate to increase the kinetic energy of injected ions, which is hoped to replace the traditional technique with high deposition rate and area without porous structure or instability. From research abroad, the LVRIP film has a low optical loss which achieve and nearly override the highest level of traditional technique with dense packing and better mechanical property, which gave it great potentialities of application in laser gyroscope. In home, a few of unites had researched the technique, and a factory is producing the LVRIP equipment for glasses, but it is far from application in laser gyroscope for the loss is too higher than traditional technique. LVRIP equipment includes three key techniques ( plasma source, electron gun-crucible system, power and control system ). Face to laser gyroscope, the paper researched two techniques of them, made two key equipments, rebuild a LVRIP coating machine based on a domestic conventional one, and made primary research of TiOj coatings. The main work and contribution of the paper include:1. Firstly researched the technique of using the large area LaBe as the emission cathode of plasma source in domestic. Aiming at the problems of high cost, high hardness and hard to machine for LaBe, a designation of no coaxial wrapping indirectly heated cathode was proposed, which benefit with low cost and overcame the difficulty of making and machining LaBe. A new machining method was put forward because of easily broken of LaBe while working, which had no hidden trouble with the material as grinding did. A plasma source was developed with an over 60A of output current, an over 6hs of cathode life in continuous work, a cost of emission cathode less than 100Y, the performance is synthetically higher than that of the other domestic units.2. Because the conventional electric gun-crucible system was not fit for LVRIP in electric and structure, a separate+labyrinth electric gun-crucible system was put forward which was fit for the gas discharge plasma working condition and increased the working pressure from 6×10-3 Pa to 2×10-1 Pa, which met the demand of LVRIP.3. Researched and solved the technical problems such as the interference of plasmasource and electric gun while linking the plasma source and the electric gun-crucible system with a domestic H44700-7 type conventional box vacuum coating machine, et al. A LVRIP experiment coating machine was built. From measurement, the mean value of saturate ion current on the surface of the global substrate holder was 0.463 mA/cm2 with an 8% inhomogeneity. While the discharge current was 30A, the machine worked stably and had a good performance.4. A primary research on TiOj coatings made with LVRIP technique was carried out. The experiment results showed that the index of refraction increased and the loss decreased with the increase of discharge current, but the homogeneity decreased by conventional toast technique. In available condition, with LVRIP coating technique, the maximum refractive index of TiO2 is 2.43 (A=633nm). The results showed that the structure of LVRIP coatings is closer, the hardness is higher, the adhesive force is stronger, and the performance is more stable than that of conventional coatings.The experiment showed that the plasma source and the electric gun techniques of LVRIP equipment have advancement and good application value. The results proved that this new technique of LVRIP could really improve the mechanical intensity and stability of coatings. Because the fund and technique were limited and simply equipped power source was adopted, the loss was high and the index of refraction was not very high. But the experiment results had shown that the index of refraction increased and the loss decrea... |
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