Measurements of nonlinear refractive indices in ceramic laser media

摘要

At the recent years a technology of ceramic laser media on the base of crystals with a cubic symmetry has been developed. The perspective of the usage of ceramic materials in many different applications including high- power short pulse lasers stimulates the work on the systematic study of the properties of these new laser media. In mis report a nonlinear refractive index, n_2, was studied for several garnet and sesquioxide laser ceramics using Z-scan method. This technique with a" top-hat" probe beam intensity distribution was used. Nonlinear indices in the range of (2-6)x10~(13) were measured for YAG ,Y_2O_3, Lu_2O_3, and Sc_2O_3 ceramic samples. These data together with the laser and spectroscopic parameters of several Nd~(3+) and Yb~(3+) doped crystals of a cubic symmetry were used to estimate in the complex the properties of laser ceramics for the application in high-power pulsed-repetitive laser - drivers for inertial confinement fusion (ICF ) program. A high heat conductivity of ceramic materials is a profitable characteristic for this application as compared to glasses which are used now for experiments in ICF at single shots regime. Compared to single crystals, ceramic elements provide laser designers with a variety of new design options for the projects of -laser-drivers. The usage of ceramic active elements with low and increased n_2 values in the channels of a powerful laser facility is discussed.