Photochemical adhesion of fused silica optical elements with no adhesive strain

An adhesive method that creates properties of heatproof, waterproof, and transparent to ultraviolet ray of 200 nm and under in the wavelength without adhesive strain was developed by putting one silica glass to another with the silicone oil that had been photo-oxidized by Xe2 excimer lamp. The measurement by the ZYGO interferometer showed that there was neither adhesive strain nor bubbles, and the bonding strength of 18MPa was achieved. To compare the heat resistance of the photo-oxidized silicone oil with that of general-purpose adhesives such as silicone rubber, water glass, and epoxy resin, the shearing tensile strength test was conducted after exposing at high temperatures from 25 to 500 °C. As a result, the silicone rubber adhesive exfoliated at 110 °C, and the epoxy resin adhesive, at 150 °C; however, the photo-oxidized silicone oil had the bonding strength of 6.5MPa at 500 °C.