Planar light valve: an 8192-channel MEMS-based spatial light modulator for high-speed amplitude and phase modulation

We report on the development of a new 2D MEMS spatial light modulator for high-speed amplitude and phase modulation targeted at UV to NIR wavelengths. The Planar Light Valve (PLV) is a 32 x 256-pixel array with programmable 7-bit control. With a frame rate of 250 kHz, the PLV is targeted at laser applications requiring high switching speed, high power handling and analog amplitude or phase control. We describe the primary technical challenges in developing the PLV including: (a) materials selection and development, (b) MEMS process design, (c) MEMS electro-mechanics and (d) CMOS driver design. For direct integration of MEMS on CMOS, we selected thermally compatible germanium and silicon-germanium. We describe how electromechanical finite element analysis was used to develop a CMOS driver with linearized response. We present preliminary test results on stroke, linearity, uniformity, efficiency, contrast, switching speed and crosstalk. We show preliminary results demonstrating focusing and beam steering by phase modulation.