Free Precession Beat of Two-Photon Induced Coherence in Atomic Rubidium Vapor

Abstract

Free precession beat of two-photon induced coherence was observed by the use of delayed probe pulses in atomic rubidium vapor. The two-photon coherence was created in the superposition state of the 5S_1⁄2 and 5D_5⁄2 levels of Rb by two-photon resonant excitation with a mode-locked dye laser pulse. The origin of the beat is attributed to the hyperfine splittings of the 5S_1⁄2 ground state of both Rb⁸⁵ and Rb⁸⁷. The observed results are explained by a theory presented in this paper.