This paper presents recent work on a VLSI-Membrane-Mirror-Light-Modulator (VLSI-MMLM) for scene projection.
This prototype spatial light modulator uses a membrane-mirror atop a custom very-large-scale integration (VLSI) chip to
modulate an off-chip light source. This modulator offers flickerless frame rates in excess of 100 Hertz and an array size
of at least 200 x 200 pixels. The modulator achieves a high-degree of compactness and portability and offers low power
operation since it uses external sources of light. Preliminary images have been projected in both the visible and midwave
infrared wavebands. This paper focuses primarily on the design, development, testing and performance of the
custom VLSI chip required for this application.
As the spatial resolution, stroke and speed requirements for advanced adaptive optics applications increase, the addressing of large numbers of electrostatic actuators for wavefront correction becomes more demanding. In this paper, we review the requirements, limits and the challenges of electrically addressing a large array of electrostatic actuators using an integrated CMOS technology. We also review the issues of high-rate data sourcing, signal channelization and multiplexing, and electronics integration (VLSI) with an eye on system power and size requirements. In examining the various CMOS technologies, we find that a broadly applicable 40V technology is currently available. Higher voltages are also available, albeit with additional design restrictions. Finally, we report preliminary work on a specific addressing scheme for a vertically-integrated VLSI/electrostatic MEMS prototype spatial phase modulator with 288x256 pixels at framing rates of 2kHz.