Applied Optics
Published by The Optical Society of America

Applied Optics Feature Announcement

Wavefront Sensing, Imaging, and Image Enhancement

Submission Deadline: 1 June 2008

This Applied Optics special feature issue, to be published in the Information Processing Division, focuses on topics of immediate relevance to the optical community. It will cover areas encompassing wavefront estimation, wavefront compensation for imaging and laser beam projection, and image postprocessing. The relevance of these topics may be seen by mentioning some major ongoing research (government and commercial) activities in which they play key roles: future extremely large telescopes for ground-based astronomy, Super-Resolution Vision System (SRVS) (DARPA program looking at imaging through deep turbulence), the atmospheric boundary layer (ABL) (where sensing and compensating for the turbulence effects are of paramount importance), and retinal imaging. To estimate and compensate for the wavefront that causes the distortion, many algorithms have been developed. These techniques can help extend the standoff range (or equivalently the size, volume, or weight requirement) of existing energy projection and beam control systems through the turbulent atmosphere by yielding a better quality image or higher irradiance on target. Imaging systems can benefit from significantly improved sensitivity and spatial resolution.

Recently, great attention has been expressed in extending the range at which imaging is performed through distorting media. One example includes horizontal path imaging where it may no longer be valid to assume that image distortion is due to phase errors close to the aperture. One of the major difficulties one is confronted with is that the isoplanatic patch may be smaller than the point spread function. Furthermore, the detected intensity profile may be highly scintillated. These examples represent major hurdles in wavefront sensing using point sources, extended targets, or laser beacons. To estimate and control the wavefront, many techniques have been proposed. Examples include Shack–Hartman, shearing interferometry, curvature sensor, point interferometry, self-reference interferometry, stochastic parallel gradient descent (SPGD), phase retrieval, and phase diversity. The applicability of one method over the other depends on atmospheric conditions, temporal and spatial bandwidth, and scene extent, to name a few. For example, for extended scenes, one may choose to use phase diversity instead of, for example, Shack–Hartman. With these estimated wavefronts, compensation may be done using phase or phase with amplitudes. If the atmosphere is extended, it may be more appropriate to use multiple deformable mirrors to estimate and compensate for the volume turbulence. Such is referred to as multiconjugate adaptive optics (MCAO). This can also be used to mitigate degradations associated with extended beacons.

This special feature will focus on the algorithms and hardware implementation. Some of the hardware platforms may include field programmable gate array (FPGA) and other commercial off-the-shelf (COTS) architecture. It will cover applications related to national defense as well as astronomical and commercial programs. Anticipated topics include but are not limited to the following:

  • High fidelity modeling of atmospheric turbulence
  • Sensing through and compensation of atmospheric turbulence
  • Postprocessing imaging of turbulence corrupted images
  • Theoretical limits in performance
  • Real-time algorithm implementation
  • Multiconjugate adaptive optics systems
  • Target-in-the-loop propagation
  • Phase conjugation techniques

Furthermore, we expect papers on wavefront sensing in applications such as eye aberration, astronomical imaging, and thermal blooming for high-energy lasers; system trade studies encompassing size, weight, and power requirements; experiments over desert and marine environments; as well as laser communication applications. As mentioned above, the relevance of wavefront sensing, imaging, and image enhancement is immediate as may be seen by various recently started government and commercial programs. This special issue will provide the readers with a succinct collection of articles that are representative of the state of the art of today’s science and technology in this fast growing arena.

Manuscripts must be prepared in standard Applied Optics format; see Information for Contributors instructions online (http://ao.osa.org/submit/style/default.cfm) or in any recent issue of Applied Optics. Please submit your manuscript electronically to the Information Processing division of Applied Optics, and specify that the manuscript is for the Wavefront Sensing feature (choose from the feature issue drop-down menu). Information on electronic manuscript submission can be found at http://ao.osa.org/journal/ao/author.cfm

Feature Editors

Jean J. Dolne
Boeing Company
Canoga Park, California
USA
jean.j.dolne@boeing.com

Brent L. Ellerbroek
Thirty Meter Telescope Project
Pasadena, California
USA
brente@caltech.edu

Michael C. Roggeman
Michigan Technological University
Houghton, Michigan
USA
mroggema@mtu.edu

Mikhail A. Vorontsov
University of Maryland at College Park
College Park, Maryland
USA
mvoronts@mail.umd.edu