Extended Range Optical Underwater Imaging Navy SBIR FY2004.2 Sol No.: Navy SBIR FY2004.2 Topic No.: N04-176 Topic Title: Extended Range Optical Underwater Imaging Proposal No.: N042-176-0 Firm: Aculight Corporation 11805 North Creek Parkway S. Suite 113 Bothell, Washington 98011 Contact: Steve Tidwell Phone: (425) 482-1100 Web Site: aculight.com Abstract: The Navy needs a compact extended range underwater imaging system that can image through > 6 attenuation lengths with 0.25" resolution. Present systems are limited by scattering to ~ 5 attenuation lengths. To meet the need, we propose a compact, adaptive raster scanner, using a doubled Yb fiber laser for the transmitter, a wide field-of-view (FOV) receiver, and an annular APD detector array, enabling adaptive data processing. The fiber laser offers excellent packaging, robustness, and output characteristics for improved S/N. The receiver offers improved collection efficiency, and the annular array adaptively balances S/N and resolution needs. The proposed system is estimated to have two decades more dynamic range than current imaging systems. Phase I is a design study on the proposed system. Optical design, together with Monte Carlo modeling simulations for various underwater scenarios, yields an optimal optical layout, and analyses of the efficiencies, S/N and resolution capabilities. We develop a preliminary packaging concept for a small underwater vehicle, together with size and weight estimates. In the Option, we define the electronics and interfaces, and develop a power budget for the complete system. The Phase I preliminary design leads to detailed design and construction of a prototype in Phase II. Benefits: The immediate benefit of the Phase I effort is that it provides a thorough preliminary design of the compact imaging system that the Navy is seeking. From the Phase I outcome, we expect to be embark on the detailed design, and then construction and testing of the imaging system in Phase II. The greatest commercial applications pertain to one piece of the imager, the fiber laser. The main applications are in machining and marking. Specific examples are via drilling, likely using the third harmonic of the fiber laser, marking of parts in high volume situation, fabrication of stents from steel tubes. In the medical community, the fiber laser or derivatives thereof will fit into various imaging modalities. A specific example is photon migration imaging, which has an oncological application in searching for cancerous and pre-cancerous lesions in large volumes of tissue. Return