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Proceedings Paper

Effects of laser-induced breakdown, self-focusing, and plasma shielding on ultrashort-pulse propagation in the eye
Author(s): Paul K. Kennedy; Ewan M. Wright; Quanyuan Feng; Kirk W. Cook; Daniel X. Hammer; Charles R. Thompson; Jerome V. Moloney; Benjamin A. Rockwell; Jeffrey J. Druessel; Alan C. Newell
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Paper Abstract

As part of a research program to understand and model eye damage produced by exposure to subnanosecond laser pulses, an effort is currently being made to model and analyze ultrashort pulse propagation from the cornea to the retina. Both analytical models and numerical simulations are being used to analyze the effects of self-focusing, laser-induced breakdown (LIB), and plasma-pulse interaction. The modeling effort is coupled with experimental measurements of LIB thresholds and plasma shielding for visible, picosecond (psec) and femtosecond (fsec) pulses in water, which serves as a reasonable simulant for the vitreous humor of the eye. Comparison of LIB thresholds to the critical power for self-focusing indicates that self-focusing has little effect on LIB thresholds for long psec pulses. For short psec and fsec pulses, however, numerical simulations show that self-focusing is critical to LIB in water. These results indicate that self-focusing may play a role in fsec pulse ocular damage, by influencing whether LIB and plasma-pulse interaction occur at the retina, in the vitreous, or both. Both the location of the LIB event and the amount of plasma shielding can significantly effect the degree of damage.

Paper Details

Date Published: 7 May 1996
PDF: 12 pages
Proc. SPIE 2681, Laser-Tissue Interaction VII, (7 May 1996); doi: 10.1117/12.239600
Show Author Affiliations
Paul K. Kennedy, Air Force Armstrong Lab. (United States)
Ewan M. Wright, Optical Sciences Ctr./Univ. of Arizona (United States)
Quanyuan Feng, Univ. of Arizona (United States)
Kirk W. Cook, Optical Sciences Ctr./Univ. of Arizona (United States)
Daniel X. Hammer, Air Force Armstrong Lab. (United States)
Charles R. Thompson, Air Force Armstrong Lab. (United States)
Jerome V. Moloney, Univ. of Arizona (United States)
Benjamin A. Rockwell, Air Force Armstrong Lab. (United States)
Jeffrey J. Druessel, Air Force Armstrong Lab. (United States)
Alan C. Newell, Univ. of Arizona (United States)


Published in SPIE Proceedings Vol. 2681:
Laser-Tissue Interaction VII
Steven L. Jacques, Editor(s)

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