A second-harmonic wave generated by an evanescent wave (SHEW) is used to measure the effective nonlinear coefficient of organic materials in powder form. The SHEW signal is less sensitive than the powder method to the phase-matching conditions of the material. For this reason, the SHEW technique can be used to survey a wide variety of samples. The effective nonlinear coefficient and the refractive indices of the sample are obtained as fitting parameters. The influence of experimental conditions on the fitting process is discussed. The results obtained from our powders are compared with the nonlinear coefficients of the same materials in bulk crystal form. Good agreement is found between experimental results and literature values.
© 1999 Optical Society of America
(160.4330) Materials : Nonlinear optical materials
(160.4760) Materials : Optical properties
(160.4890) Materials : Organic materials
(190.2620) Nonlinear optics : Harmonic generation and mixing
(190.4710) Nonlinear optics : Optical nonlinearities in organic materials
R. Kremer, A. Boudrioua, J. C. Loulergue, and A. Iltis, "Effective nonlinear coefficients of organic powders measured by second-harmonic generation in total reflection: numerical and experimental analysis," J. Opt. Soc. Am. B 16, 83-89 (1999)