Direct interferometric measurements of the nonlinear refractive index coefficient n2 in laser materials

Abstract

To properly account for nonlinear propagation effects in the design of a large laser system, it is necessary to know the nonlinear refractive index coefficient n₂ of each system component. We report values of n₂ for YAG, ED‐2 laser glass, EY‐1 Faraday rotator glass, and FR‐4 rotator glass. The measurements were made at 1.06 μm using a time‐resolved Mach‐Zehnder interferometer to directly observe the variation of refractive index with intensity during the transmission of pulses 150 psec in duration.