Water-cooled stacked-actuator flexible mirror for high-power laser beam correction

To correct for phase distortions in high-power laser setups a stacked-actuator deformable mirror with water cooling was developed. The main characteristics of the mirror such as the initial surface profile, response functions of the actuators, maximal stroke and amplitude frequency characteristic were shown. The quality of initial surface was equal to 0.14 µm (P-V). The maximal stroke of the mirror was about 7 µm. The first resonant frequency was found at 18.5 kHz, that would allow to exploit such wavefront corrector in high-speed adaptive optical systems. The measured hysteresis of the deformable mirror was equal to 12%. Experimental investigations of proposed cooling method of the mirror surface through actuators were performed.