Electromagnetically Induced Transparency with Noisy Lasers

Abstract

We demonstrate and characterize two coherent phenomena that can mitigate the effects of laser phase noise for Electromagnetically Induced Transparency (EIT): a laser-power-broadening-resistant resonance in the transmitted intensity cross-correlation between EIT optical fields; and a resonant suppression of the conversion of laser phase noise to intensity noise when one-photon noise dominates over two-photon-detuning noise. Our experimental observations are in good agreement with both an intuitive physical picture and numerical calculations. The results have wide-ranging applications to spectroscopy, atomic clocks and magnetometers.