Calibration Issues with Shack-Hartman Sensors for Metrology Applications

John E Greivenkamp, Daniel G. Smith, Eric Goodwin

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Scopus citations

Abstract

A long-standing goal of optical metrology is testing aspherics without the need for part-specific null lenses. The problem involves increasing the measurement dynamic range while preserving accuracy. The Shack-Hartmann wavefront sensor offers an interesting alternative to interferometry where the dynamic range is tied to the wavelength of light. Because the Shack-Hartmann wavefront sensor is a geometric test, the lenslet array can be designed in a way that trades sensitivity for dynamic range making it possible to test, without a null, aspheres that would otherwise require null optics. However, a system with this much dynamic range will have special calibration issues. Shack-Hartmann wavefront sensors are widely used in feedback control systems for adaptive optics. In that application, calibration is not a serious problem as the system drives the correction to a null; calibration errors slow the rate of convergence. For metrology applications, the calibration of the Shack-Hartmann wavefront sensor must be absolute. This presentation will discuss issues related to the design and calibration of a Shack-Hartmann metrology system including the design of an appropriate lenslet array, methods for dealing with induced aberrations, vignetting and spatial resolution limitations.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
EditorsR. Geyl, D. Rimmer, L. Wang
Pages372-380
Number of pages9
Volume5252
DOIs
Publication statusPublished - 2004
EventOptical Fabrication, Testing, and Metrology - St. Etienne, France
Duration: Sep 30 2003Oct 3 2003

Other

OtherOptical Fabrication, Testing, and Metrology
CountryFrance
CitySt. Etienne
Period9/30/0310/3/03

    Fingerprint

Keywords

  • Aspheres
  • Optical Testing
  • Shack-Hartmann
  • Wavefront Sensors

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Greivenkamp, J. E., Smith, D. G., & Goodwin, E. (2004). Calibration Issues with Shack-Hartman Sensors for Metrology Applications. In R. Geyl, D. Rimmer, & L. Wang (Eds.), Proceedings of SPIE - The International Society for Optical Engineering (Vol. 5252, pp. 372-380) https://doi.org/10.1117/12.513462