SBIR-STTR Award

This small Business Innovation Research (SBIR) Phase I project will demonstrate the ability to coat a microelectromechanical systems (MEMS) deformable mirror (DM) array with high-reflectance dielectric coatings. Micromachined DMs provide unprecedented control over an optical beam, however, they cannot sustain operation with lasers of more than a few hundred milliwatts because of the relatively low reflectance of the typical metallic optical coatings. The dielectric coated MEMS DMs developed with this research will be able to handle tens of Watts of laser power commensurate with many laser machining applications. Normally, a dielectric coating would render a MEMS based mirror useless because residual stresses in these thick coatings warp the mirror surface. Even simple single-wavelength coatings with 99.75% reflectance are relatively thick (3-5 times the wavelength of interest) compared to typical MEMS layer thicknesses. To achieve a high-quality mirror surface, this research will fabricate novel MEMS DMs with a stress-compensation layer that balances residual stresses from the dielectric coatings. The stress compensation layer enables the DMs to be coated with well-established and readily available coatings. Mirrors with these coatings will be tested at high laser fluence to determine failure points and validate thermal models of the DM. The broader impact/commercial potential of this project is to enhance the capabilities of microelectromechanical systems (MEMS) deformable mirrors (DM) to make them suitable for use in industrial applications. Deformable mirrors offer high-resolution control of an optical beam spatially and temporally. This ability has led to tremendous technical and scientific advances in astronomy, retinal imaging, and microscopy. The research here will expand the capabilities of low-cost MEMS DMs to provide exquisite wavefront control to applications where relatively high power (1-100 W) lasers are employed. For astronomers, the DM will be used to pre-compensate laser guide star beams for atmospheric turbulence to improve AO performance of 10-30m class telescopes. These increases in performance will enable astronomers to probe deeper into the universe. The same technology can be employed to enhance laser-machining equipment for the electronics and semiconductor industries. Applications for this equipment include via drilling for ceramic packages, through- silicon vias (TSV), laser machining of high-density flex circuits, integrated-circuit trimming of resistors, and cutting of links in DRAMs. For these applications, the DM can provide fast focus corrections and on-the-fly beam shaping to tailor the beam for the task at hand

What is the proposed innovation? This Small Business Innovation Research (SBIR) Phase II project will advance the state of the art in compact 360-degree camera systems, achieving sizes of about 1/8 of current systems, without compromising the quality or resolution of the optics. Convex mirror based optics has resulted in the realization of very high-resolution ultra-wide angle camera systems. A fundamental limitation in these systems has been the size of the optics in relation to the size of the imaging sensor. Mirror diameters in the range of 10 times the size of the sensor have been achieved. The objective of this research is to overcome the above limitation and achieve mirror diameters at the level of 3-5 times the size of the sensor, keeping ultra high resolution across the entire field of view. In this Phase II project, a miniature high-resolution 360-degree prototype system including optics and camera sensor will be built to demonstrate this capability.What are the broader/commercial impacts of the proposed innovation? The broader impact of this project will be will to increase the market reach of ultra-wide angle cameras for multiple applications, including video-conferencing, robotics and home surveillance. This new approach to designing optics will result in substantially reducing the form factor of high-resolution wide-angle optics. The high-resolution camera sensors available in the consumer market today can be better used in very small ultra-wide angle video cameras with the ability for multiple remote users to decide where they want to look independent of each other. This has the potential of transforming the market for pan-tilt-zoom cameras to "solid-state pan/tilt/zoom" cameras. The very low size, weight and power cameras that would result from this research can result in small wireless, battery powered systems that would increase the proliferation of cameras for a variety of different applications.