Amplitude and phase beam characterization using a two-dimensional wavefront sensor

Daniel R. Neal, W. J. Alford, James K. Gruetzner, Mial E. Warren

Research output: Contribution to journalConference articlepeer-review

67 Scopus citations


We have developed a two-dimensional Shack-Hartman wavefront sensor that uses binary optic lenslet arrays to directly measure the wavefront slope (phase gradient) and amplitude of the laser beam. This sensor uses an array of lenslets that dissects the beam into a number of samples. The focal spot location of each of these lenslets (measured by a CCD camera) is related to the incoming wavefront slope over the lenslet. By integrating these measurements over the laser aperture, the wavefront or phase distribution can be determined. Since the power focused by each lenslet is also easily determined, this allows a complete measurement of the intensity and phase distribution of the laser beam. Furthermore, all the information is obtained in a single measurement. Knowing the complete scalar field of the beam allows the detailed prediction of the actual beam's characteristics along its propagation path. In particular, the space-beamwidth product, M2, can be obtained in a single measurement. The intensity and phase information can be used in concert with information about other elements in the optical train to predict the beam size, shape, phase and other characteristics anywhere in the optical train. We present preliminary measurements of an Ar+ laser beam and associated M2 calculations.

Original languageEnglish (US)
Pages (from-to)72-82
Number of pages11
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - Nov 20 1996
Externally publishedYes
Event3rd International Workshop on Laser Beam and Optics Characterization 1996 - Quebec City, Canada
Duration: Jul 8 1996Jul 10 1996


  • Beam quality
  • Binary optics
  • Diffractive optics
  • Laser beam characterization
  • Laser beam diagnostics
  • M
  • Microlens arrays
  • Shack-hartmann sensor
  • Wavefront sensor

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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