Wavefront control of the large optics test and integration site (LOTIS) 6.5 m Collimator

Steven C. West, Samuel H. Bailey, James H. Burge, Brian Cuerden, Jeff Hagen, Hubert M. Martin, Michael T. Tuell

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


The LOTIS Collimator provides scene projection within a 6.5 m diameter collimated beam used for optical testing research in air and vacuum. Diffraction-limited performance (0.4 to 5 μm 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 6.5 m collimated beam.

Original languageEnglish (US)
Pages (from-to)3522-3537
Number of pages16
JournalApplied optics
Issue number18
StatePublished - Jun 20 2010

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Engineering (miscellaneous)
  • Electrical and Electronic Engineering


Dive into the research topics of 'Wavefront control of the large optics test and integration site (LOTIS) 6.5 m Collimator'. Together they form a unique fingerprint.

Cite this