@article{oai:repo.qst.go.jp:00080658,
 author = {Miyasaka, Yasuhiro and Kondo, Kotaro and Kiriyama, Hiromitsu and Yasuhiro, Miyasaka and Kotaro, Kondo and Hiromitsu, Kiriyama},
 issue = {9},
 journal = {Crystals},
 month = {Sep},
 note = {The importance of heat-resistant optics is increasing as the average power of high-intensity lasers increases. A silicon carbide (SiC) ceramic with high thermal conductivity is proposed as an optics substrate to suppress the thermal effect. The temperature rise of the substrate and the change in the surface accuracy of the mirror surface, which degrade the laser beam quality, are investigated. Gold mirrors on synthetic fused silica and SiC ceramic substrates are heated with a 532 nm wavelength laser diode. The synthetic fused silica substrate placed on an aluminum block shows a temperature increase by ~32 °C and a large temperature gradient. In contrast, the SiC ceramic substrate shows a uniform temperature distribution and a temperature increase by only ~4 °C with an absorbed power of ~2 W after 20 min laser irradiation. The surface accuracy (roughness) of the synthetic fused silica changes from /21.8 (29.0 nm) to /7.2 (88.0 nm), increasing by a factor of ~3.0 due to the expansion of the center. However, that of the SiC ceramic mirror changes from /21.0 (30.2 nm) to /13.3 (47.7 nm), increasing by a factor of ~1.6 while maintaining the same temperature distribution after laser irradiation.},
 title = {High-thermal-conductivity SiC ceramic mirror for high-average-power laser system},
 volume = {10},
 year = {2020}
}