<title>Deformable mirrors for high-power lasers</title>

We describe the performance of a bulk micromachined deformable mirror coated with a dielectric stack for adaptive optics applications with high power lasers. A reflectance of greater than 99.9% was measured and the mirror had a residual static aberration of less than 90 nm rms primarily in astigmatism. A thermally induced distortion of 71 nm RMS was observed for an incident intensity of 300 W/cm<SUP>2</SUP> and an average power of 57 W. The multi-layer coated deformable mirror survived over half a billion cycles without degradation and survived for 30 hours with 36 W cw 1064 nm laser light. In addition, the thermally induced distortion with 22 W of average laser power (350 W/cm<SUP>2</SUP>) was reduced from 88 nm to 31 nm rms.