Micromachined silicon deformable mirror

Abstract

A new silicon deformable mirror design is presented which provides high reflectivity, an optical quality continuous surface, and high intensity handling capacity. Its features make it useful for a wide range of devices including telescopes, leasers, and photolithographic systems. The mirror architecture is similar to commercial electrostrictive deformable mirrors. A focus corrector built using this architecture exhibited 2.25 microns of actuation at the center through the application of 100v corresponding to a radius of curvature of -2.4m. A 30 micrometers thick 1cm diameter silicon mirrors exhibited its first mechanical resonance at 2.7kHz. A mirror coated with 100nm of gold was shown to be able to withstand 100kW/cm² of continuous wave 1064nm intensity for 10 minutes without observable degradation. An active mode-matching experiment was performed showing that 99.5 percent of a Nd:YAG beam could be coupled to a finesse 4000 ring cavity.