Strongly Phase-Aberrated Nondiffraction Limited Laser Beams
Abstract
Both amplitude and phase aberrations usually alter and reduce the intensity of the focal plane distribution of an optical system. Phase fluctuations are generally the more important; if the square root of the ensemble averaged phase variance sigma squared sub l is less than 0.1 wavelength, the reduction in maximum irradiance is given quite well by exp -4 pi squared sigma squared sub l almost without regard to the correlation size of the phase fluctuation. For larger phase distortions, this simple formula will predict a very severe intensity reduction that may be much too pessimistic. In this situation, a careful accounting of the influence of the relative size of the phase correlation length is necessary for an accurate prediction of the intensity reduction. It can be shown, then, that the irradiance profile of the strongly phase aberrated beam can be written approximately as the direct sum of two beams, the respective characteristics of which depend on the phase variance and correlation length.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1976
- Accession Number
- ADA020310
Entities
People
- Charles B. Hogge
Organizations
- Air Force Research Laboratory