EIT-enhanced nonlinear Kerr index of refraction of Rb vapor measured in an optical cavity

Abstract

Summary form only given. We present our recent results in measuring the nonlinear Kerr index of refraction of multi-level rubidium atoms inside an optical ring cavity. By using a similar experimental arrangement as we used previously to demonstrate cavity linewidth narrowing due to EIT inside an optical ring cavity, we can measure the nonlinear coefficient χ/sup (3)/ through the asymmetric transmission profile of the ring cavity. By measuring the degree of asymmetry, we can obtain the Kerr nonlinear index of refraction directly, without worrying about contributions from linear absorption. Our preliminary results indicate a significant enhancement of Kerr nonlinearity due to atomic coherence at near-resonance conditions. We present our experimental results and their comparison with theoretical calculations. We discuss the implications of this enhanced nonlinear Kerr index of refraction to nonlinear optical processes in an optical cavity.