Open AccessPhase correlation between four-wave mixing and optical fields in double Λ-type atomic system
Author(s) -
Taek Jeong,
Han Seb Moon
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.028774
Subject(s) - four wave mixing , physics , laser linewidth , atomic coherence , optics , coherence (philosophical gambling strategy) , photon , laser , phase noise , interferometry , electromagnetically induced transparency , atomic physics , nonlinear optics , quantum mechanics
We study the spectral features and phase of four-wave mixing (FWM) light according to the relative phase-noise of the optical fields coupled to a double Λ-type atomic system of the 5S 1/2 -5P 1/2 transition of 87 Rb atoms. We observe that the spectral shape of the FWM spectrum is identical to that of the two-photon absorption (TPA) spectrum due to two-photon coherence and that it is independent of the relative phase-noise of the pump light. From these results, we clarify that the two-photon coherence plays a very important role in the FWM process. Furthermore, we measure the relative linewidth of the FWM signal to the probe and pump lasers by means of a beat interferometer. We confirmed that the phase of the FWM signal is strongly correlated with that of the pump laser under the condition of phase-locked probe and coupling lasers for two-photon coherence.