Surface Mapping Using Real-time Two color Holography

The U.S. Navy requires an instrument to study the abrasion and eros ion of undersea cables. We propose to build a novel optical device that will accurately map the surface and compute the volume of small depressions on diffusely reflecting surfaces such as cylindrical cables. The instrument is based on the use of two-color holographic contouring. The latest advances in photorefractive materials, automated interferogram reduction, and laser diode technology can be combined into a real-time, quantitative, and robust instrument. Our innovative design incorporates a novel photorefractive material that allows in-situ recording, development and erasure of holograms at video frame rates, advanced data reduction algorithms that facilitate quantitative measurements, and compact diode laser sources that make the device lightweight and inexpensive. The Phase I study will demonstrate the acquisition of profile data from sample objects using an optical breadboard. Phase II research would deliver a prototype system to the Navy. The system would lend itself to a wide variety of applications in industry and the military as an inspection and fabrication tool. In addition to mapping surface flaws, profile measurements could be integrated with CAD/CAM for automated reproduction of complex shapes.