Z-scan analysis for high order nonlinearities through Gaussian decomposition

In the present work the Gaussian decomposition (GD) method, used as a theoretical infrastructure in analyzing z-scan experiments, is extended to higher order nonlinearities. The general case of a high power elliptic Gaussian beam, able to excite many different orders of refractive nonlinearity is considered. The very interesting in practice situation of the excitation of the first two orders of nonlinearity is analyzed. Furthermore, numerical simulations are performed and an experimental process for the determination of the coefficients related to the second-order refractive nonlinearities is suggested. (C) 2003 Elsevier B.V. All rights reserved.