Components of the third-order nonlinear susceptibi ity tensors in KDP, DKDP and LiNbO3 nonlinear optical crystals

摘要

The ratio of the components of the third order nonlinear susceptibility tensors (which are responsible for the self-action effects) in KDP, DKDP and LiNbO3 crystals is measured at the 1064-nm wavelength of a Nd : YAG laser. Measurements were made on the basis of analysis of polarisation dependences of the focused radiation transmission by the z-scan method. The obtained polarisation dependences of the effective Kerr nonlinearity correspond to a tensor of the fourth rank that is symmetric in all its indices. The measured values of the Kerr nonlinearities that are responsible for the self-action of o-polarised radiation were found to be (1.75+/-0.55) x 10(-14) and (2.4+/-0.8) x 10(-13) esu for KDP and LiNbO3 crystals, respectively.