We report on the design, fabrication, and implementation of a single-layer resonant waveguide-grating (RWG) mirror on a sapphire substrate. Our goal is to enhance these optics capability to withstand high intra-cavity power densities by exploiting the superior thermal properties of sapphire. The RWG was implemented as an intra-cavity folding mirror in an Yb:YAG thin-disk laser to generate linearly polarized and spectrally stabilized radiation. A linearly polarized output power of 191 W with an optical efficiency of 39% was obtained in multi-mode operation. This corresponds to a power density of 52 kW/cm² on the RWG, for which the increase of its surface temperature was measured to be 12 K, which resulted in a 46-fold reduction of the surface temperature rise dependence on the intra-cavity power density with respect to what has been reported for a RWG on a fused silica substrate. In near fundamental-mode operation, a linearly polarized emission with an output power of 90 W, an optical efficiency of 30%, and a spectral bandwidth of 28 pm FWHM was obtained.

我们报告了蓝宝石衬底上单层谐振波导光栅（RWG）镜的设计、制造和实现。我们的目标是通过利用蓝宝石卓越的热性能来增强这些光学器件的能力，以承受高腔内功率密度。RWG 在 Yb:YAG 薄盘激光器中作为腔内折叠镜实现，以产生线偏振和光谱稳定的辐射。在多模操作中获得了 191 W 的线偏振输出功率和 39% 的光学效率。这对应于RWG上52kW/cm ²的功率密度，其表面温度的增加被测量为12K，这使得表面温升对腔内的依赖性降低了46倍相对于已报道的熔融石英基板上的 RWG 的功率密度。在近基模工作中，获得了输出功率为90 W、光学效率为30%、光谱带宽为28 pm FWHM的线偏振发射。