| This dissertation describes the development of kilo-pixel micro-electro-mechanical optical-quality surface-micromachined deformable mirrors and spatial light modulators along with scalable control electronics. These silicon-based deformable mirrors have the potential to modulate spatial and temporal features of an optical wavefront with applications in imaging, beam-forming, and optical communication systems. Techniques to improve the manufacturing, quality, and capability of these mirrors are detailed. The new mirror system was characterized and a scalable control system was developed to coordinate and control a large array of mirrors.; Three types of kilo-pixel deformable mirrors were created: continuous membrane, segmented membrane, and a hybrid stress-relieved membrane mirrors. This new class of mirrors, deformed using electrostatically actuated surface-normal actuators, have an aperature of 10 mm, a stroke of 2 mum, position repeatability of 3 nm, surface roughness of 12 nm, reflectivity of 91%, and a bandwidth in air of 7 kHz. A custom fabrication process was developed in tandem with a new mirror design to address design and layout issues including packaging, residual stress, reliability, yield, fill factor, and surface topography.; A chemo-mechanical polishing process improved the surface quality of the mirrors by decreasing surface roughness from an RMS value of 46nm to 12nm. A gold coating process increased reflectivity from 42% to greater than 91% without introducing a significant amount of stress in the mirror membrane. An alternative actuator design and layout was also developed that achieved an increased stroke of 6 mum, with the potential for even longer stroke with stress reduction. The long stroke capability was realized through introduction of split electrodes, actuation membrane cuts, and a double stacked anchor architecture.; A computer-driven electronic system was developed to aid in the electro-mechanical testing of these deformable mirrors. Quasi-static mirror characterization included voltage versus deflection measurements and optical surface quality measurements. Dynamic measurements included frequency response in air and vacuum, actuator repeatability, and high-speed real-time imaging of a single spatial light modulator pixel.; A single channel controller was developed to dynamically control a single pixel in a spatial light modulator array. Results from this controller demonstrated the feasibility for a scalable parallel processor system. A newly-developed multi-processor parallel gradient descent control algorithm was demonstrated in the controller. This multichannel system is inherently scalable to a kilo-pixel control system, and can be used as a tool for future research into high speed AO control. |
