Abstract

The residual wave-front error after correction by an adaptive optics system (AOS) with a laser guide star (LGS) as reference for the wave-front sensing is computed by using the wave-front expansion on the Zernike polynomials. The polynomial angular correlations are calculated for a spherical wave front coming from the LGS used to compensate for a plane wave front coming from a natural star and also for two arbitrary spherical wave fronts. The plot of decorrelation versus angular distance between the natural star and the LGS is much steeper for the sodium LGS than for the Rayleigh LGS. A D/n dependence is found for the 50% correlation angle, where D is the telescope diameter and n is the polynomial radial degree. For focal anisoplanatism a modal d0 parameter [d0(J)] is computed versus J, the number of corrected polynomials. The Rayleigh LGS has the capacity for large-field-of-view observations but with poor image quality and a low-order AOS, while the sodium LGS is suitable for high-image-quality observations with a high-order AOS but at the price of a small field of view. The isoplanatic angle is computed for different D and observation wavelengths. For D =8 m and a sodium LGS, the wavelength must be larger than 1.6 μm in order to produce a λ/5 wave-front error.

© 1997 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Optimal modal wave-front compensation for anisoplanatism in adaptive optics

Matthew R. Whiteley, Byron M. Welsh, and Michael C. Roggemann
J. Opt. Soc. Am. A 15(8) 2097-2106 (1998)

Adaptive optics with four laser guide stars: correction of the cone effect in large telescopes

Elise Viard, Miska Le Louarn, and Norbert Hubin
Appl. Opt. 41(1) 11-20 (2002)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (13)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Tables (4)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (88)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription