Fabrication of silica glass microchannel reflectors by 3D printing and UV-curing

The thermal deformation of silica glass reflectors employed in high-power laser systems has emerged as a critical issue, imposing limitations on the scalability of lasers to achieve high average power and high beam quality. Water-cooling is the most effective and commonly employed method for reducing thermal deformation. However, it is challenging to create embedded microchannels for water-cooling in silica glass by conventional processing methods. In this study, we demonstrate a novel method for fabricating silica glass microchannel reflectors by combining glass slurry UV-curing with 3D printing of polymeric microchannels. The glass slurry consists of SiO₂ nanoparticles and organic resins, which can be UV-cured and subsequently transformed into fused silica glass through heat treatment. During the UV-curing process, the 3D printed polymeric microchannel structure is embedded within the glass slurry. Subsequently, in the heat treatment process, the polymeric microchannel structure is removed, leaving behind the corresponding hollow cavity. The photocurable resin used for printing microchannels is optimized to ensure a crack-free sample. The sintered sample shows an isotropic shrinkage of 28%. Microchannel structures with different shapes are created. The water tightness of the fabricated reflectors is validated by injecting red ink into the microchannels.