High Temporal Bandwidth Optical Wavefront Sensor Technologies

Airborne-based high-energy-laser (HEL) applications are currently receiving serious consideration for both theater defense and tactical systems operations. One of the most critical shortcomings in these undertakings is the ability to sense and correct foraero-optic distrotions to the exiting beam. While these shortcomings in adaptive-optic correction for aero-optical flow transmission are apparent, there is an even more fundamental issue that needs to be addressed; there currently do not exist laboratoryinstruments that can acquire wavefornts at sufficient bandwidth to quantify and characterize the spatial and temporal frquencies of optical wavefront distrotion for transmission through aero-optical flow fields. Such an insturment may be used inwind-tunnel experiments and in aircraft-to-aircraft flight tests to quantify the magnitude of the aero-optic problem and/or to assess the merit of flow-tailoring mearures such as passive and active flow control. Phase I results have established thefeasibility of a 2-D, 20-kHz real-time/50-kHz post-processed optical wavefront sensor which can satisfy fundamental testing requirements for high-speed aero-optic corrections. Such a ground-based diagnostic insturment will be of considerable value to theaero-optic/adaptive-optic communtity, and is an important enbling technology for a real-time, high-speed, flight-based, oprational wavefornt sensor.