This Small Business Technology Transfer (STTR) Phase I project will determine the feasibility of a novel holographic wave front sensing device. The advantage of this modal holographic wave front sensor is that it optically processes the incoming wave front, automatically generating the coefficients for the feedback signal. This is in contrast to other approaches, which rely on conventional computers to perform the processor intensive wave front expansions before feedback. By using holographic optical processing, the wave front sensor can be made to operate on a much faster time scale allowing for device operation in regimes of heavy turbulence or in extremely high resolution, large aperture systems. Other advantages include reduced size, complexity, and cost of the overall wave front device, allowing for more sensors, actuators and larger closed loop bandwidths for a given fixed budget. The technical work plan includes performance analysis of a multi-channel wave front sensing device, actual testing and measurements on a multi-channel device, examination of the major issues and barriers to practicality, and a full system device design and feasibility study.
There are a variety of applications that would benefit from extremely fast, highly complex (i.e. a large number of sensors and actuators) adaptive optics systems. Scientific and government applications include imaging satellites and spacecraft through turbulent atmospheres as well as compensating atmospheric turbulence in astronomical imaging. There has also been substantial interest in adaptive optics for the projection of laser beams through the atmosphere, providing highly focused spots on targets several hundreds of kilometers away. Similar applications, both beaming and imaging, can be envisioned through highly turbulent flows. In each of these major application areas, there is a push towards larger aperture or sparse aperture systems to increase both the light gathering capability and the resolving power of the system. Ultimately, there is a large need for faster adaptive optics systems that are capable of driving hundreds to thousands of actuators at very high closed loop bandwidths. This proposal will enhance scientific knowledge on holographic optical processing and how such technology can be used to create such an applicable, reduced complexity, low cost adaptive optics systems.
