Low Order Aberrations in Band-Limited Lyot Coronagraphs

Details Low Order Aberrations in Band-Limited Lyot Coronagraphs Low Order Aberrations in Band-Limited Lyot Coronagraphs

2005-07-22

arxiv.org/abs/astro-ph/0507539v1

Astrophys.J.634:1416,2005

Astronomy and Astrophysics

Astrophysics

8 pages, 3 figures, 1 table; ApJ accepted

Scientific paper

10.1086/466507

We study the way Lyot coronagraphs with unapodized entrance pupils respond to small, low order phase aberrations. This study is applicable to ground-based adaptive optics coronagraphs operating at 90% and higher Strehl ratios, as well as to some space-based coronagraphs with intrinsically higher Strehl ratio imaging. We utilize a second order expansion of the monochromatic point-spread function (written as a power spectrum of a power series in the phase aberration over clear aperture) to derive analytical expressions for the response of a `band-limited' Lyot coronagraph (BLC) to small, low order, phase aberrations. The BLC possesses a focal plane mask with an occulting spot whose opacity profile is a spatially band-limited function rather than a hard-edged, opaque disk. The BLC is, to first order, insensitive to tilt and astigmatism. Undersizing the stop in the re-imaged pupil plane (the Lyot plane) following the focal plane mask can alleviate second order effects of astigmatism, at the expense of system throughput and angular resolution. The optimal degree of such undersizing depends on individual instrument designs and goals. Our analytical work engenders physical insight, and complements existing numerical work on this subject. Our methods can be extended to treat the passage of higher order aberrations through band-limited Lyot coronagraphs, by using our polynomial decomposition or an analogous Fourier approach.

Affiliated with

Also associated with

No associations

Rating

Low Order Aberrations in Band-Limited Lyot Coronagraphs does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Low Order Aberrations in Band-Limited Lyot Coronagraphs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Low Order Aberrations in Band-Limited Lyot Coronagraphs will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-706451