Abstract

With the advent of adaptive optical imaging systems it has become possible to compensate for the deleterious effects of the atmosphere. Many researchers have quantified the performance of adaptive optical systems with respect to wavefront sensor noise, finite wavefront sampling, finite degrees of freedom in the wavefront reconstruction device, and anisoplanatism. Here we study the performance degradation due to the finite temporal response of the adaptive optical system. As expected, the degradation is a strong function of the time delay between wavefront sensing and wavefront correction. In addition we find that the degradation is a strong function of the aperture size as well as whether overall wavefront tilt is removed. We also find that the degree of compensation is a factor in determining the level of performance degradation. Many of the earlier studies of the effect of time delay are restricted to cases in which neither overall piston or tilt are removed.^1,2 These prior results are pessimistic in terms of quantifying the degradation experienced for a given time delay. Our results show that for an aperture of diameter 10r_o the time delay can be as large as 0.7r_o/v where r_o is the Fried coherence diameter and v is the velocity of the turbulence.

© 1991 Optical Society of America