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

摘要

We report a theoretical study of the Z-scan technique by using quasi-one-dimensional slit beams for characterizing third-order optical nonlinearity. We verify that the sensitivity of this Z-scan scheme is roughly the same level as top-hat beams and is greatly higher than Gaussian beams by a factor of approximately 2.5. This scheme should have the capability to measure less than a lambda/500 wave-front distortion at least. Numerical formulas obtained in theory allow direct estimation of nonlinear refraction and absorption coefficients from the normalized peak-valley transmittance difference measured. Some salient features are also discussed. This Z-scan scheme is also demonstrated experimentally. (C) 2004 Optical Society of America