Title

Interplay between self-focusing and high-order multiphoton absorption

Authors

Authors

S. Polyakov; F. Yoshino;G. Stegeman

Abbreviated Journal Title

J. Opt. Soc. Am. B-Opt. Phys.

Keywords

BEAM; Optics

Abstract

We study the distortion of optical beams that is due to the combined effects of strong self-focusing and three- and four-photon absorption, a situation that exists, for example, in the polydiacetylene bis-paratoluene sulfonate (PTS). The characteristic nonlinear distances were defined for each process. Theoretical analysis of the beam propagation leads to two distinct limits, one limit dominated by self-focusing and the other by higher-order absorption. Propagation was studied analytically and numerically for ew and pulsed beams in these two limits and for cases in which both nonlinear effects are important. It was found that beam distortion caused by multiphoton absorption and refraction leads to situations in which diffraction plays an important role, even for input beams whose diffraction length is much larger than the sample length. It was concluded that, for the typical intensities used in Z-scan measurements, nonlinear processes and diffraction contribute simultaneously to beam distortion and must be taken into account. (C) 2001 Optical Society of America.

Journal Title

Journal of the Optical Society of America B-Optical Physics

Volume

18

Issue/Number

12

Publication Date

1-1-2001

Document Type

Article

Language

English

First Page

1891

Last Page

1895

WOS Identifier

WOS:000172669400018

ISSN

0740-3224

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