Abstract

The performance of an adaptive optics system using a single laser guide star is constrained by laser guide star anisoplanatism and the characteristics of available lasers. Improved performance is theoretically achievable through the use of multiple laser guide stars. Earlier results on wavefront reconstruction in laser guide star systems¹ are extended to this more general case. General reconstruction algorithms are evaluated using a linear systems model which accounts for the partially correlated effects of laser guide star anisoplanatism, laser guide star position uncertainty, wavefront sensor noise, deformable mirror fitting error, aperture edge effects and control loop servo bandwidth. Reconstructor wavefront estimation accuracy is optimized subject to linear constraints imposed to insure control loop stability. Reconstructor performance is quantified in terms of the optical system’s modulation transfer function for a system including a 3.5-m primary, a deformable mirror with from 341 to 771 actuators, and a constellation of one or several laser guide stars. The addition of a single, low power, resonant sodium guide star greatly improves the performance of a system using multiple Rayleigh backscatter laser guide stars.

© 1991 Optical Society of America