Time-resolved deformation measurement of Yb:YAG thin disk using wavefront sensor

Even though thin-disk medium mounted on a diamond substrate is generally used for high average power operation, we found that the pulsed pumping of the Yb:YAG thin-disk mounded on a copper-tungsten heatsink could improve both optical-to-optical O-O efficiency and beam quality. We are expecting that the increase of O-O efficiency is caused by the suppression of ASE. However, the mechanism of beam quality improvement is not clear. We developed a precise measurement system of thin-disk deformations based on a Hartmann-Shack wavefront sensor. Investigating thin-disk dynamics under pulsed pumping can help to greatly improve the mode matching and allow obtaining higher output energy.