Speckle lifetimes in high-contrast adaptive optics

Bruce Macintosh; Lisa Poyneer; Anand Sivaramakrishnan; Christian Marois

doi:10.1117/12.627854

8 October 2005 Speckle lifetimes in high-contrast adaptive optics

Bruce Macintosh, Lisa Poyneer, Anand Sivaramakrishnan, Christian Marois

Proceedings Volume 5903, Astronomical Adaptive Optics Systems and Applications II; 59030J (2005) https://doi.org/10.1117/12.627854
Event: Optics and Photonics 2005, 2005, San Diego, California, United States

Abstract

The main noise source in detection of faint companions such as extrasolar planets near bright stars with AO is speckle noise--residual PSF structure caused by wavefront errors due to the atmosphere, the AO system, and static optical effects. Of these, the most fundamental are atmospheric speckles--even given infinite wavefront SNR and a perfect DM, timelag between sensing and correction will always lead to a residual atmospheric speckle pattern. There have been several suggestions as to the lifetime of these atmospheric speckles, none strongly supported by theory or simulation. We have carried out a systematic series of simulations and analysis to explore this question. We show that speckles have different behavior in the regime in which diffraction is significant (first-order speckles, which are rapidly modulated as a phase error translates across the aperture) and in the coronagraphic regime (second-order speckles, which evolve only as the phase screen completely clears the aperture.). We use simulations to analyze the behavior of speckles in a variety of regimes, showing that the second-order atmospheric speckle lifetime is almost constant irrespective of the properties of the AO system, and is set primarily by the atmospheric clearing time of the telescope aperture.

Citation Download Citation

Bruce Macintosh, Lisa Poyneer, Anand Sivaramakrishnan, and Christian Marois "Speckle lifetimes in high-contrast adaptive optics", Proc. SPIE 5903, Astronomical Adaptive Optics Systems and Applications II, 59030J (8 October 2005); https://doi.org/10.1117/12.627854

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available