Scanning Second-Order Holographic Laser Acoustic System

To address the U.S. Army's need for a self-aiming laser acoustic target designator/classifier, Physical Optics Corporation (POC) proposes to develop a new Second-order Scanning Holographic Laser Acoustic (SOHLA) system. SOHLA will be based on integration of uniquely designed aberration-corrected, high-efficiency, scanning single- or multibeam holographic telescopic optics (antenna) with unique laser acoustic sensing, second-order holographic interferometry (photorefractive crystal) and a tracking subsystem to place a laser-lock on a target. Second order holography has the unique advantages of real-time monitoring and the self-referencing effect of photorefractive nonlinear crystals or polymers, remarkably reducing the coherence and stability requirements of vibrometry and holographic systems. Thus, the resulting sensor is totally immune to vibration and environmental variations of the medium, and adaptable to changes in beam direction. In Phase I POC will demonstrate the feasibility of SOHLA laser scanning classification/tracking by fabricating a single laser scanning telescopic system for operation at a wavelength of 785 nm, integrated with a laser acoustic holographic sensing system and array of directional microphones. Phase II will produce a practical, field-deployable, self-aiming laser acoustic target designator with a fully developed target classification database.