title: Experimental comparison of a Shack-Hartmann sensor and a phase-shifting interferometer for large-optics metrology applications.
abstract: We performed a direct side-by-side comparison of a Shack-Hartmann wave-front sensor and a phase-shifting interferometer for the purpose of characterizing large optics. An expansion telescope of our own design allowed us to measure the surface figure of a 400-mm-square mirror with both instruments simultaneously. The Shack-Hartmann sensor produced data that closely matched the interferometer data over spatial scales appropriate for the lenslet spacing, and much of the <20-nm rms systematic difference between the two measurements was due to diffraction artifacts that were present in the interferometer data but not in the Shack-Hartmann sensor data. The results suggest that Shack-Hartmann sensors could replace phase-shifting interferometers for many applications, with particular advantages for large-optic metrology.
authors: Lawrence Livermore National Laboratory, University of California, P.O. Box 808, L-481, Livermore, California 94551, USA. koch1@llnl.gov
authors: J A
authors: JA
authors: Koch
authors: R W
authors: RW
authors: Presta
authors: R A
authors: RA
authors: Sacks
authors: R A
authors: RA
authors: Zacharias
authors: E S
authors: ES
authors: Bliss
authors: M J
authors: MJ
authors: Dailey
authors: M
authors: M
authors: Feldman
authors: A A
authors: AA
authors: Grey
authors: F R
authors: FR
authors: Holdener
authors: J T
authors: JT
authors: Salmon
authors: L G
authors: LG
authors: Seppala
authors: J S
authors: JS
authors: Toeppen
authors: L
authors: L
authors: Van Atta
authors: B M
authors: BM
authors: Van Wonterghem
authors: W T
authors: WT
authors: Whistler
authors: S E
authors: SE
authors: Winters
authors: B W
authors: BW
authors: Woods