Intracavity Beam Control in Laser Resonators

Most directed energy weapons systems separate beam clean-up and atmospheric compensation into two (or more) separate adaptive optics (AO) systems. This approach arose for a variety of reasons. The aberration structure of the high energy laser (HEL) is significantly different than that of the atmosphere resulting in different requirements on the deformable mirror and the wavefront sensors. The limited throw of the deformable mirror was thought to be insufficient to solve both problems simultaneously. If this could be accomplished, there would be significant gains in cost, complexity, size, and weight. We propose here to investigate a system architecture that would enable both the beam clean-up and the atmospheric compensation to be combined into a single AO system. Our approach involves leveraging the versatile distorted grating wavefront sensor (DGWFS) developed by Kestrel Corporation and a new deformable mirror technology developed by Active Optical Systems. We will begin Phase I of this effort with a detailed modeling and simulation effort that will investigate the efficacy of the proposed approach. The Phase I effort will conclude with a scaled-down laboratory demonstration of the approach. In Phase II, we propose to demonstrate a working system.