Adaptive Zoom Collimator Design and Risk Reduction

Ground-based testing of air / space-borne sensors & trackers (SBIRS, GMD, THAAD, etc.) requires achromatic optical collimation systems that can project dynamic scenes & targets at very large apparent distances. The collimation system must undergo major adjustments to optimally accommodate the FOV of various test articles, but the projection quality is extremely sensitive to misalignment of the large mirror optics which are inherently difficult to set or maintain. In addition, the cryovacuum environment required for low radiometric background makes typical lab-bench access impossible. The AEDC Space Chambers need a high-performance, all-reflective zoom collimator rated for cryovacuum conditions. Nutronics, Inc. proposes to design a reflective cryovacuum zoom collimator with adaptive optical (AO) compensation to meet AEDC’s requirements. A system of movable curved mirrors plus a deformable mirror (DM) conveys a broad-spectrum scene at infinite conjugate distance to the sensor under test, with a clear aperture > 30 cm and zoom ratio of at least 4:1 up to 10:1 to accommodate various test articles, while a probe beam and wavefront sensor are used to provide AO feedback. This design-only effort leverages extensive Nutronics expertise in the field of AO, as well as experience with large reflective optics and optics in cryovacuum environments.