1. Adaptive optics package designed for astronomical use with a laser guide star tuned to an absorption line of atomic sodium
- Author
-
Stephen D. Mostek, Jen Nan Wong, Charles D. Swift, J. Thaddeus Salmon, Carolyn L. Weinzapfel, Kenneth E. Waltjen, Donald T. Gavel, Rodney J. Rinnert, Kenneth Avicola, Herbert W. Friedman, John W. Bergum, R. W. Presta, Claire E. Max, Scot S. Olivier, and James M. Brase
- Subjects
Physics ,Wavefront ,Speckle pattern ,Optics ,Tilt (optics) ,Laser guide star ,business.industry ,Strehl ratio ,Wavefront sensor ,business ,Adaptive optics ,Deformable mirror - Abstract
We present the design and implementation of a very compact adaptive optics system that senses the return light from a sodium guide-star and controls a deformable mirror and a pointing mirror to compensate atmospheric perturbations in the wavefront. The deformable mirror has 19 electrostrictive actuators and triangular subapertures. The wavefront sensor is a Hartmann sensor with lenslets on triangular centers. The high-bandwidth steering mirror assembly incorporates an analog controller that samples the tilt with an avalanche photodiode quad cell. An f/25 imaging leg focuses the light into a science camera that can either obtain long-exposure images or speckle data. In laboratory tests overall Strehl ratios were improved by a factor of 3 when a mylar sheet was used as an aberrator. The crossover frequency at unity gain is 30 Hz.
- Published
- 1994
- Full Text
- View/download PDF