We have developed a precision adhesive that is UV-curable and durable and has low shrinkage during curing and a low coefficient of thermal expansion. This new adhesive consists of a cycloaliphatic diepoxy acetal, a triarylsulfonium-SbF6, an epoxy silane coupling agent and a synthetic cordierite filler. With an optimized amount of filler, this adhesive can be cured completely in about five minutes with less than 2% shrinkage by exposure to UV irradiation. The cured adhesive exhibits a low coefficient of thermal expansion of less than 2 x 10(-5)/degrees C, high glass transition temperatures of 200 degrees C, and excellent durability in boiling water and moisture. Thus, the adhesive can replace welding in the fabrication of optical components that require sub-micrometer positioning accuracy.