VUV photon induced strain free amorphous silica coating with hard protective waterproof property for high power laser op
- PDF / 1,834,687 Bytes
- 6 Pages / 595.28 x 841.89 pts (A4) Page_size
- 35 Downloads / 138 Views
VUV photon induced strain free amorphous silica coating with hard protective waterproof property for high power laser optics Yuji Sato1, Shinji Motokoshi1, Masahiro Nakatsuka1, Yoshiaki Okamoto2 and Masataka Murahara3,4 1 Institute for Laser Technology 1-8-4 Utsubo-honmachi, Nishi-ku, Osaka, 550-0004 Japan 2 Okamoto optics co. ltd 8-34 Haramachi, Isogo-ku, Yokohama, Kanagawa, 235-0008 Japan 3 Innovative Research Initiatives, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8552 Japan 4 Tokai University, 4-1-1 Kitakaname, Hiratsuka-shi, Kanagawa, 259-1292 Japan
ABSTRACT An amorphous silica film has been coated on a fused silica glass and KH2PO4 [KDP] crystal by using the photo oxidization of Dimethy-siloxane silicone [DMSS] oil by using a xenon [Xe2] excimer lamp at room temperature. The DMSS oil [-O-Si[CH3]2-O-]n was spin-coated on a fused silica glass to make a thin film, and the Xe2 lamp light was vertically irradiated in the presence of oxygen. Thus, the organic oil was changed into inorganic glass. In order to investigate the photochemical reaction process, the fluorescence intensity was measured by spectrometer at actual time and the new method to form a transparent, photo-oxidized thin film efficiently has been established. The interferometer analysis was conducted to investigate the strain of the coating samples. It became clear that the no strain were caused by vitrification of the silicone oil on the fused silica galass with Xe2 lamp irradiation. INTRODUCTION Silicon dioxide [SiO2] coatings are widely used as protective film for mirrors, lenses, and crystals because of having the transparent, hard, and resistant to environmental elements. It is, in general, necessary to elevate the temperature of a substrate in order to form a hard film using a deposition method [1-6]. Mahajan et al. deposited a SiO2 film on the silicon wafer by plasmaenhanced chemical vapor deposition [PECVD] method using tetra-ethoxy-silane [TEOS] in oxygen atmosphere when maintaining the substrate temperature at 300 degrees centigrade [4]. Dennler et al. also deposited a SiO2 film on the polyimide substrate by PECVD method in the presence of the gases, which consists of 1to 9 mixture of hexamethyl-disiloxane [HMDSO] and O2 gas [5]. Although these produce a hard coating, it causes the particles being vapor-deposited to lose energy upon deposition to create a porous structure. However, these methods require the substrates at high temperatures above 400 degrees centigrade, which occur the heat strain. Meanwhile, the sol-gel coating methods are used as hard coating methods with low heating temperature. C.M.Chan et al. was reported that silica-based hard coating was conducted and investigated on the modified polyester substrates below 150 degree centigrade [6]. At present, the substrate temperature is controlled around 400degree centigrade because the property of the substrate changes with the treatment; there exists no film except the photo-oxide film of silicone
oil that is resistant against laser, strong in adhesiv
Data Loading...
