Abstract

We have extended the conventional Z-scan theory by employing an aberration-free approximation of a Gaussian beam through a nonlinear medium and derived a simple analytical formula for Z-scan transmittance, including the effects of both nonlinear absorption and nonlinear refraction, which could be applicable to the sample with large nonlinear phase shifts. We verified the extended Z-scan theory in an amorphous chalcogenide ${\mathrm{As}}_2{\mathrm{S}}_3$ thin film by measuring the Z-scan transmittance with both open and closed apertures. The nonlinear refractive index $\gamma =7.6\times {10}^{-5} {\mathrm{cm}}^2/\mathrm{W}$ and the nonlinear absorption coefficient $\beta =1.6 \mathrm{cm}/\mathrm{W}$ of ${\mathrm{As}}_2{\mathrm{S}}_3$ were measured at subbandgap 633-nm illumination.

© 1999 Optical Society of America

Determination of photo-induced changes in linear optical coefficients by the Z-scan technique

K. Fedus and G. Boudebs
J. Opt. Soc. Am. B 26(11) 2171-2175 (2009)

Diffraction-efficiency oscillations in amorphous As₂S₃ films

O. Nordman, A. Ozols, and N. Nordman
J. Opt. Soc. Am. B 16(4) 631-636 (1999)

Time-resolved Z-scan measurements of optical nonlinearities

J. Wang, M. Sheik-Bahae, A. A. Said, D. J. Hagan, and E. W. Van Stryland
J. Opt. Soc. Am. B 11(6) 1009-1017 (1994)

Z-scan technique for characterizing third-order optical nonlinearity by use of quasi-one-dimensional slit beams

Bing Gu, Jun Yan, Qin Wang, Jing-Liang He, and Hui-Tian Wang
J. Opt. Soc. Am. B 21(5) 968-972 (2004)

Reflection Z-scan technique for the study of nonlinear refraction and absorption of a single interface and thin film

D. V. Petrov
J. Opt. Soc. Am. B 13(7) 1491-1498 (1996)