Design of a Large Pupil Relief Broadband Collimator for use in a MMW/IR HWIL Facility

Optical Sciences Corporation has designed and implemented a 116 inch exit pupil relief optical system for dynamic infrared scene projection to flight table mounted seekers at the U.S. Army Missile Command (AMCOM) Research, Development, and Engineering Center (RDEC). The optical system collimates the output from a 512x512 element resistor array in the 35μm waveband. The large pupil stand-off is necessary to support projector operation in a millimeter wave (MMW) anechoic chamber. The facility is designed to stimulate a common aperture, dual-band seeker with millimeter wave and IR imagery via a dichroic beam combiner. The dichroic beam combiner is located in the anechoic chamber and reflects the IR scene while transmitting MMW signals. The optical system exhibits distortion of less than 0.5% over the full field of view and chromatic focal shift of less than 10% of the diffraction limited range. The performance of the system is limited by the diffraction limit. This document describes the simulation environment and arrangement, outlines the design procedure from predesign and achromatization to final tolerancing, and presents final test data and sample imagery.