Performance of a spectral beam combining grating with YAG substrate

In a previous study, the temperature-rise of a spectral beam combining grating was analyzed theoretically and experimentally. It was concluded that the temperature of a grating can be effectively reduced by increasing the substrate thickness or by using a substrate material with higher thermal conductivity. In this study, yttrium aluminum garnet (YAG) was used as the substrate material to fabricate a spectral beam combining grating. The temperature, distortion, and far-field beam quality of the YAG-substrate-grating were analyzed theoretically and experimentally. It is concluded that, compared with the traditional quartz-substrate-grating, not only can the YAG-substrate-MDG withstand higher power, but the beam quality of the diffraction laser is also better.