Wavefront control of the large optics test and integration site (LOTIS) 6.5m collimator.
The LOTIS Collimator provides scene projection within a 6.5m diameter collimated beam used for optical testing research in air and vacuum. Diffraction-limited performance (0.4 to 5microm wavelength) requires active wavefront control of the alignment and primary mirror shape. A hexapod corrects secondary mirror alignment using measurements from collimated sources directed into the system with nine scanning pentaprisms. The primary mirror shape is controlled with 104 adjustable force actuators based on figure measurements from a center-of-curvature test. A variation of the Hartmann test measures slopes by monitoring the reflections from 36 small mirrors bonded to the optical surface of the primary mirror. The Hartmann source and detector are located at the f/15 Cassegrain focus. Initial operation has demonstrated a closed-loop 110 nm rms wavefront error in ambient air over the 6.5m collimated beam.
West
Steven C
SC
Steward Observatory, University of Arizona, Tucson, Arizona 85721, USA. scwest@email.arizona.edu
Bailey
Samuel H
SH
Burge
James H
JH
Cuerden
Brian
B
Hagen
Jeff
J
Martin
Hubert M
HM
Tuell
Michael T
MT