title: Calibration of a Shack-Hartmann sensor for absolute measurements of wavefronts.
abstract: We demonstrate a method with which to calibrate a Shack-Hartmann sensor for absolute wavefront measurement of collimated laser beams. Nearly perfect spherical wavefronts originating from a single-mode fiber were used as references. After the calibration, the uncertainty of the wavefront was less than lambda/100 peak to valley across a diameter of 6 mm. For example, this method allowed us to balance aberrations and prepare collimated beams with wavefronts that are plane to lambda/500 across 1 mm.
authors.affiliation: Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Chernyshov
authors.forename: Uwe
authors.initials: U
authors.lastname: Sterr
authors.forename: Fritz
authors.initials: F
authors.lastname: Riehle
authors.forename: Jürgen
authors.initials: J
authors.lastname: Helmcke
authors.forename: Johannes
authors.initials: J
authors.lastname: Pfund