Multilayer nanostructured coatings with non-linear optical response for manipulation of high energy coherent beams

It is important for United States to maintain an asymmetric warfighting advantage throughout its armed forces by having both advanced weaponry and defense capabilities in all strategic scenarios. High Energy Laser (HEL) capabilities have been demonstrated both domestically and abroad and represent a unique directed energy weapon with speed-of-light attack capability, potentially rendering many technologies ineffective or obsolete.  Therefore, to maintain strategic global dominance, we must provide a defense solution against this advancing class of weapons. The cumulative work of Phase I & II has yielded the development of a non-sacrificial reflective optical limiter which mitigates laser damage with an intrinsically higher damage tolerance than a traditional absorptive optical limiter. Current results have demonstrated a system concept at a variety of potential HEL wavelengths, including visible, NIR, and SWIR, and is further tailorable to MWIR and LWIR. Multi-bandpass and broadband mirrors have been developed to enable usage in complex sensor systems and simultaneously protect against several common HEL wavelengths. Preliminary HEL testing has shown coatings withstanding the maximum available irradiance with no signs of failure or change in performance.  The proposed Phase IIS work will expand on these results through application specific development and environmental testing and will culminate in tailored coatings supplied on prototype geometries. Environmental testing includes HEL multi-hit, thermomechanical, and high-G durability testing. Application specific development includes the optimization of nonlinear optical behavior for tailored dynamic range, as well as prototype scaling and testing.