Abstract
In segmented-mirror telescopes, wave-front discontinuities caused by segment misalignment are a major problem because they severely degrade optical performance. While angular misalignments are usually measured with deflectometric wave-front sensors (e.g., Shack-Hartmann sensors), a number of techniques have been proposed for the measurement of vertical discontinuities (pistons). In earlier papers we presented an instrument called UPC-ZEBRA that uses a novel interferometric technique to measure piston error during the daytime with an uncertainty of 5 nm within a 30-μm range. Here we present the most representative results obtained during the testing stage and a detailed analysis of error sources. The main modifications to be introduced for the instrument’s use as a phasing calibration system are also outlined.
© 2004 Optical Society of America
Full Article | PDF ArticleMore Like This
Carles Pizarro, Josep Arasa, Ferran Laguarta, Núria Tomàs, and Agustí Pintó
Appl. Opt. 41(22) 4562-4570 (2002)
Achim Schumacher, Nicholas Devaney, and Luzma Montoya
Appl. Opt. 41(7) 1297-1307 (2002)
Agustí Pintó and Ferran Laguarta
Appl. Opt. 45(26) 6694-6701 (2006)