Four-wave mixing in a non-degenerate four-level diamond configuration in the hyperfine Paschen–Back regime

AbstractWe present an experimental study of seeded four-wave mixing (4WM) using a diamond excitation scheme (with states from the 5S1/2,5P1/2,5P3/2 and 5D3/2 terms) in a thermal vapour of 87Rb atoms. We investigate the 4WM spectra under the application of a strong magnetic field (0.6 T). The Zeeman interaction is strong enough to realize the hyperfine Paschen–Back regime, which has the effect of separating the optical transitions by more than the Doppler width, thereby significantly simplifying the spectral features. We show that this facilitates a quantitative comparison, even in the regime of strong dressing, between experimental data and a simple theoretical model based only on four-level optical Bloch equations.