Micromachined SLM based on pixelated reflective membranes

摘要

Abstract: We report on an on-chip projection-type spatial light modulator that consists of a continuous reflective surface formed by a thin stretched silicon nitride membrane supported by a grid structure providing an array of individually accessible deformable pixels. The curvature of each pixel can be controlled electrostatically by changing the potentials on underlying integrated electrodes. This type of modulator can be used directly as a phase modulator (possibly combined with a microlens array) and in dark schlieren projection scheme as a display device. The continuous surface of the membrane provides 100% optical fill factor and, being appropriately coated, can handle high optical loads over a wide spectral range, including the infrared region. The support grid structure and electronics can be scaled so as to achieve a wide range of resolutions with a uniform technology. Integrated control electronics and the deformable pixelated mirror structure are fabricated independently on different wafers, allowing optimized fabrication of each and ensuring higher yield and quality and lower costs.!5