Compact High Energy Laser (HEL) Beam Director

In the Phase I of the project we studied feasibility of utilizing unique capabilities of diffractive waveplates – the new, fourth generation of optics  – for development of thin, flat and compact, window-mountable and light-weight, high-efficiency and high pointing accuracy, fast systems with millisecond re-pointing capability for high energy beam delivery for submarines. Several device architectures have been identified for conventional and novel emerging threats such as hypersonic missiles and swarms of boats and drones. Gimbals and other conventional beam directors are not fast enough for directing the beam and with random access to multiple fast moving targets, are not scalable and/or do not have high enough radiation damage thresholds. The objective of the Phase 2 of the proposal is to fabricate and test the most promising device architectures identified in the Phase 1 work that best meet technology requirements for submarines related to limitations in sizes and compatibility with operation in marine environments. Optimizing beam director architecture for maximizing beam diameter over the required field of regard (FOR) for a given beam director window size, fabricating, testing and delivering deployable prototype devices are the main objectives of the Phase 2 work along with the analysis of novel capabilities related with sharing the high-energy laser aperture with a short-wave infrared (SWIR) or mid-wave infrared (MWIR) surveillance sensor. The risk that flat optics will be susceptible to damage by high energy laser beams was mitigated in Phase I by demonstrating damage thresholds for CW radiation at 1.064 µm wavelength far higher than needed for use in multi-kilowatt class laser beams systems. Additional laser damage testing will be performed during Phase I Option and Phase 2. Optical aperture diameter up to 6” demonstrated during Phase I will be scaled to 8” and up to 12” diameter.