@inproceedings{243f1a11475345d8983570197c7d0a19,
title = "A high-Strehl low-resolution optical imager (BESSEL): A measurement of the inner scale of turbulence",
abstract = "We have constructed a high-speed image stabilization system, BESSEL, that is capable of performing wavefront correction at a rate exceeding 1 kHz. BESSEL achieved on-sky Strehl ratios of 98-99% at 800 nm as we approached the inner scale of atmospheric turbulence when the refractor telescope aperture was stopped down to 25.4 mm {\~(}r0/2). This is better than expected from Kolmogorov theory, indicating that at D{\~ }r0/2 we are within the inner scale of turbulence. Utilizing high Strehls and the technique of roll subtraction enabled BESSEL to resolve the binary, ADS 10418AB, with separation of only 0.71 ?/D and a delta magnitude of{\~ }3 mags at 800 nm. BESSEL's capability to produce high Strehls ratios means that the instrument can be used to test the performance of interference/phase coronagraphs on-sky for the first time. Integrated with an optical vortex coronagraph, BESSEL is capable of nulling the first airy ring of Betelgeuse by more then a factor of ten.",
keywords = "Coronagraphy, Instrumentation: adaptive optics, Stars: binaries, Stars: planetary systems",
author = "Peters, {Mary Anne} and Close, {Laird M.} and Tom Stalcup and Matt Rademacher and Swartzlander, {Grover A.} and Ford, {Erin L.} and Abdul-Malik, {Rukiah S.}",
year = "2008",
doi = "10.1117/12.789592",
language = "English (US)",
isbn = "9780819472250",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
booktitle = "Adaptive Optics Systems",
note = "Adaptive Optics Systems ; Conference date: 23-06-2008 Through 26-06-2008",
}