Onboard High Speed Wavefront Sensors for Airborne Directed Energy Applications

The U.S. Air Force has a national defense-related mission to aid in the development of airborne laser-based weapons and interceptors and is at the forefront of aero-optical testing and evaluation of wavefront sensors that can quantify and counteract wavefront aberration effects to enhance the ability of airborne laser weapons in delivering kill energy for target decimation. This Phase I effort develops, integrates, and demonstrates the state-of-the-art technology that can enable the construction of a high-speed wavefront sensor to be deployed in a transonic aircraft with sufficient frequency response, temporal and spatial resolution to produce high-speed readout signals for aero-optical aberration corrections using deformable mirrors that can make a critical difference in the effectiveness of an airborne laser weapon. We propose to deliver to the U.S. Air Force the complete design of a state-of-the-art wavefront sensor prototype for deployment in a transonic airborne vehicle that can provide the most powerful capabilities for aero-optics in existence. The proposed effort focuses on two different methodologies; Shack Hartman wavefront sensing and, specifically, a new interferometry technology made possible by digital holography and high-speed detectors. The work plan will consist of conducting breadboard experiments to establish the technical feasibility of each approach based on sampling resolution and adapting the designs to a custom-built, high-speed detector to assess spatial resolution, real-time algorithm speed, correction accuracy and onboard integration between the two wavefront sensing methodologies. The capability and compactness of these systems will be used to evaluate the more favorable technique that will be further refined and tested for demonstration of meeting solicitation requirements. In addition, long-range beam propagation experiments will be performed to validate MetroLaser’s model for laser attenuation, reflectivity and divergence radiometric profilometry and establish the sensitivity requirements for practical application of the wavefront sensor. The project will build upon theoretical, experimental, and engineering results from previous works, and the experience from the in-house product development and commercial sales of high-speed wavefront sensors and digital holography instruments. The effort is expected to provide a direct comparison between the widely used Hartman wavefront sensing and an interferometry technique that will provide the potential for the development and deployment of a completely new and promising high-speed sensor architecture to provide wavefront distortion measurements for laser-based weapons.