Breadboard testing of a phase-conjugate engine with an interferometric wave-front sensor and a microelectromechanical systems-based spatial light modulator

Abstract

Laboratory breadboard results of a high-speed adaptive-optics system are presented. The wave-front sensor for the adaptive-optics system is based on a quadrature interferometer, which directly measures the turbulence-induced phase aberrations. The spatial light modulator used in the phase-conjugate engine was a microelectromechanical systems-based piston-only correction device with 1024 actuators. Laboratory experiments were conducted with this system utilizing Kolmogorov phase screens to simulate atmospheric phase distortions. The adaptive-optics system achieved correction speeds in excess of 800 Hz and Strehl ratios greater than 0.5 with the Kolmogorov phase screens.

High-Contrast Imaging using Adaptive Optics for Extrasolar Planet Detection

“…I have characterized the yield and actuator uniformity, which contribute to better calibration and provide feedback for device improvements. The most recent device has 99.5% normal actuators, which is a dramatic improvement over the early segmented device with 94.1% normal actuators [43].…”

“…Micro-electrical-mechanical-systems (MEMS) DMs, such as those manufactured Testbed work was also done with the 1024-actuator segmented device using Kolmogorov phase screens to introduce abberations [43]. A major limitation of this earlier segmented MEMS device was the number of inactive actuators.…”

“…There are many other types of WFS, including curvature systems [39], pyramid WFS [42] and interferometers of various types [39,43].…”

Interferometric adaptive optics for high-power laser pointing, wavefront control, and phasing

“…6,7,8 This DARPA project in turn had its roots in work performed at the Northrop Gruman Corp. on interferometric tracking systems. 9 The CCIT project developed both the interferometric adaptive optics system at Lawrence Livermore National Laboratory and also the MEMS deformable mirrors at Boston Micromachines Corporation.…”

Design and progress toward a multiconjugate adaptive optics system for distributed aberration correction

“…The process of manufacturing phase plates via binary glass etching has been used previously 4 and this particular process was developed at LLNL for the Coherent Communications Imaging and Targeting project. 5,6 The Laboratory for Adaptive Optics loaned the original phase plate for the purpose of investigating this technique of manufacturing the phase plates which is approximately an order of magnitude less expensive than the glass etching process. The process of glass etching is described in the next paragraphs followed by a description of the optical epoxy replication process and characterization work done on the replicated phase screens.…”