A new type of wavefront sensor for adaptive optics with pulsed laser beacons

University Of Arizona, Tucson AZ

Investigators

Abstract

Lloyd-Hart AST9987358 Abstract A very innovative approach to sense an atmospheric wavefront distortion with Rayleigh beacons is being developed. A near diffraction-limited laser emitting ultra-violet pulses of < 100 nanoseconds will project columns of light whose instantaneous volume is a near cylindrical shape < 30 meters long by < 10 centimeters wide within the optical wavefront-phase perturbing atmospheric medium. A portion of the turbulent atmosphere is frozen in time by the <100 nanosecond pulse. Radiation will Rayleigh backscatter optical phase information characteristic of that volume into the telescope. This scene information will be used to create a real-time volumetric tomographic map of the 3-D character of the turbulence. Signals from this volume phase map will drive a multiple-plane Adaptive-Optics system to correct for atmospheric turbulence over a wide isoplanatic patch. Systems design and limited hardware prototypes will be designed built and tested to verify theory. An important aspect of this innovative idea is how well do the theoretical expectations for wavefront accuracy and resolution can be realized on an astronomical telescope such as the 6.5-meter MMT.