Accession Number:

ADA504245

Title:

Optical Phase Unwrapping in the Presence of Branch Points

Descriptive Note:

Journal article

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s):

Report Date:

2008-05-12

Pagination or Media Count:

15.0

Abstract:

Strong turbulence causes phase discontinuities known as branch points in an optical field. These discontinuities complicate the phase unwrapping necessary to apply phase corrections onto a deformable mirror in an adaptive optics AO system. This paper proposes a non-optimal but effective and implementable phase unwrapping method for optical fields containing branch points. This method first applies a least-squares LS unwrapper to the field which isolates and unwraps the LS component of the field. Four modulo-2-pi-equivalent non-LS components are created by subtracting the LS component from the original field and then restricting the result to differing ranges. 2-pi phase jumps known as branch cuts are isolated to the non-LS components and the different non-LS realizations have different branch cut placements. The best placement of branch cuts is determined by finding the non-LS realization with the lowest normalized cut length and adding it to the LS component.

Subject Categories:

  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE