Non-degenerate four-wave mixing in rubidium vapor: transient regime

TL;DR

This paper studies the transient behavior of four-wave mixing in rubidium vapor, revealing fast decay and oscillations influenced by atomic motion, detunings, and field intensities, with a model aligning qualitatively with experiments.

Contribution

It introduces a simplified model that accounts for atomic thermal motion, propagation, absorption, and dispersion to explain transient FWM responses in rubidium vapor.

Findings

Fast decay times and oscillations depend on detunings and intensities.

Atomic velocity classes significantly influence transient behavior.

Qualitative agreement between model and experimental results.

Abstract

We investigate the transient response of the generated light from Four-Wave Mixing (FWM) in the diamond configuration using a step-down field excitation. The transients show fast decay times and oscillations that depend on the detunings and intensities of the fields. A simplified model taking into account the thermal motion of the atoms, propagation, absorption and dispersion effects shows qualitative agreement with the experimental observations with the energy levels in rubidium (5S1/2, 5P1/2, 5P3/2 and 6S1/2). The atomic polarization comes from all the contributions of different velocity classes of atoms in the ensemble modifying dramatically the total transient behavior of the light from FWM.