Submersible High Energy Laser Beam Director

To create a compact high energy laser (HEL) system for installation in a submarine mast, it is essential that the optical elements of the beam director be as close as possible to the window separating the HEL system from the maritime environment. Conventional beam pointers, such as those based on gimbaled mirrors, require windows much larger than the HEL beam diameter if a field of regard larger than a few tens of degrees must be addressed. A non-conventional beam pointer based on diffractive elements placed immediately adjacent to the window would allow a more practical window size, making the overall HEL system much more compact for a given HEL beam size than would be the case with a conventional beam director. We propose development of a beam pointing system based on diffractive waveplate devices to achieve a compact, affordable HEL system. A fast steering mirror on the beam path can serve to both reduce beam jitter and provide fine steering of the beam. A deformable mirror and closed-loop tracking of a the return from a pilot beam illuminating the target can provide compensation for atmospheric turbulence and thermal blooming.