Fast Wavefront Sensing for Mitigating Aero-Optical Effects

Aero-optical and aero-mechanical disturbances are a fundamental challenge to implementing and operating a laser weapon system (LWS) on an aircraft platform. If strategies for mitigating or controlling these disturbances are not incorporated, aero-optic disturbances can severely curtail the military utility of airborne directed energy weapon systems (DEWS). One possible means of compensating aero-optic disturbances is to use adaptive optics (AO) control as part of the airborne LWS beam control system (BCS) design. Presently, conventional AO systems struggle to compensate aero-optics because the characteristic frequencies of aero-optic disturbances (1?10 kHz) are too fast for AO systems with commercial-off-the-shelf (COTS) camera-based sensing solutions to be effective. To overcome the current frame-rate limitations of state-of-the-art AO systems, MZA will leverage our expertise in model-based system engineering and beam control system hardware construction to design, construct, and test a photodiode-based wavefront sensor concept for adaptive optic control in an airborne application.  Our approach will utilize appropriate modeling and simulation activities to guide the design of a solution which meets frame rate, sensitivity, dynamic range, size, weight, and power requirements.  The goal of the Phase I program is to of a prototype design for a high-bandwidth wavefront sensor for use in a real-time adaptive optics controller. To achieve this, MZA will perform radiometry modeling in SHaRE to establish sensor sensitivity requirements and sensor performance requirements that would need to be meet in a DEWS. Alongside the modeling and system analysis activity, we will develop a preliminary system design and construct a small prototype WFS.  This small prototype WFS will be bench tested in the laboratory characterize the temporal and radiometric performance of the sensor, and to validate our sensor design philosophy. MZA will develop plans for integrating the fast photodiode sensor hardware with existing DM systems to affect closed-loop AO compensation of aero-optic disturbances.  It is anticipated that this design will yield a high-speed WFS with improved SNR which will enable effective AO compensation for airborne DEWS in engagement scenarios with military utility.