title: Interferometric characterization and modeling of pathlength errors resulting from beamwalk across mirror surfaces in LISA.
abstract: An alternative payload concept with in-field pointing for the laser interferometer space antenna utilizes an actuated mirror in the telescope for beam tracking to the distant satellite. This actuation generates optical pathlength variations due to the resulting beamwalk over the surface of subsequent optical components, which could possibly have a detrimental influence on the accuracy of the measurement instrument. We have experimentally characterized such pathlength errors caused by a λ/10 mirror surface and used the results to validate a theoretical model. This model is then applied to predict the impact of this effect for the current optical design of the LISA off-axis wide-field telescope.
authors.affiliation: Astrium GmbH-Satellites, Friedrichshafen, Germany. harald.koegel@astrium.eads.net
authors.forename: Harald
authors.initials: H
authors.lastname: Kögel
authors.forename: Domenico
authors.initials: D
authors.lastname: Gerardi
authors.forename: Joep
authors.initials: J
authors.lastname: Pijnenburg
authors.forename: Martin
authors.initials: M
authors.lastname: Gohlke
authors.forename: Thilo
authors.initials: T
authors.lastname: Schuldt
authors.forename: Ulrich
authors.initials: U
authors.lastname: Johann
authors.forename: Claus
authors.initials: C
authors.lastname: Braxmaier
authors.forename: Dennis
authors.initials: D
authors.lastname: Weise