Micromachined deformable mirrors for laser wavefront control

High-power lasers are used today for a wide variety of commercial and scientific applications from laser machining to gravitational-wave detection. Many high power lasers typically suffer from reduced beam quality due to thermally induced aberrations. Results are presented showing the shape and magnitude of thermally induced aberrations in a transmissive optic and in a slab laser amplifier. Calculations are performed showing the effect of these aberrations on the power in the lowest-order Hermite-Gauss mode. Experimental results showing 50% power loss due to thermally induced aberrations in a transmissive optic is presented. Several different types of electrostatically actuated micromachined deformable mirrors that were developed to compensate for laser aberrations. One such mirror was used to compensate the aberrations induced on laser wavefront by a slab laser amplifier. The deformable mirror was able to remove the aberrations such that the power in the lowest-order Hermite-Gauss mode increased from 31% to 89%.