Rq. Fugate et al., 2 GENERATIONS OF LASER-GUIDE-STAR ADAPTIVE-OPTICS EXPERIMENTS AT THE STARFIRE OPTICAL-RANGE, Journal of the Optical Society of America. A, Optics, image science,and vision., 11(1), 1994, pp. 310-324
We report results that were obtained with two generations (Generation
I and Generation II) of a laser-guide-star adaptive-optics system that
is capable of continuous compensation at 65-Hz (Generation I) and 130
-Hz (Generation II) closed-loop bandwidths on a 1.5-m telescope. We us
ed a copper-vapor laser that was focused at a 10-km range as the laser
guide star and a range-gated Shack-Hartmann sensor to operate a conti
nuous-facesheet deformable mirror that controlled either 149 or 241 ac
tuators. We used a separate full-aperture sensor and a steering mirror
to remove overall tilt. System performance was measured by imaging st
ars with a high-resolution CCD camera in a narrow spectral band that w
as centered at 0.88 mu m, from which we computed point-spread function
s, optical transfer functions, and Strehl ratios. Using the laser guid
e star, we achieved a FWHM image resolution of 0.13 arcsec and a Streh
l ratio of 0.48. Using a natural guide star, we achieved a Strehl rati
o of 0.64 at 0.13 arcsec FWHM resolution. We also obtained compensated
images of the Trapezium region in Orion in H-alpha light, using only
the laser guide star.