Measuring the refractive-index nonlinearity coefficient of glasses used in the optical channel of high-power lasers

摘要

This paper proposes a new method of determining the refractive-index nonlinearity coefficient n_2 of glasses, based on the direct observation of the self-action of a powerful probe beam in a nonlinear medium. It is shown that the new KGSS-0180/35 phosphate laser glass possesses a nonlinearity coefficient n_2 almost a factor of 2 less than that of GLS-22 phosphate glass, which is widely used in domestically produced laser installations. The new glass also has a lower n_2 value than that of standard K8 optical glass, but somewhat greater than that of fused quartz.