Transient dynamics of nonlinear magneto-optical rotation

TL;DR

This paper investigates the transient behavior of nonlinear magneto-optical rotation in rubidium vapor, demonstrating how varying magnetic-field sweep rates influence signal characteristics and providing a detailed theoretical and experimental analysis.

Contribution

It introduces a comprehensive study of NMOR transient dynamics under different sweep rates and light intensities, supported by density-matrix calculations for quantitative understanding.

Findings

Transition from dispersive to oscillating signals with increased sweep rate

Strong dependence of signals on magnetic-sweep rate and light intensity

Identification of static and oscillatory components in NMOR signals

Abstract

We analyze nonlinear magneto-optical rotation (NMOR) in rubidium vapor subjected to continuously-scanned magnetic field. By varying magnetic-field sweep rate, a transition from traditionally-observed dispersive-like NMOR signals (low sweep rate) to oscillating signals (higher sweep rates) is demonstrated. The transient oscillatory behavior is studied versus light and magnetic-field parameters, revealing a strong dependence of the signals on magnetic-sweep rate and light intensity. The experimental results are supported with density-matrix calculations, which enable quantitative analysis of the effect. Fitting of the signals simulated versus different parameters with a theoretically-motivated curve reveals presence of oscillatory and static components in the signals. The components depend differently on the system parameters, which suggests their distinct nature. The investigations provide insight into dynamics of ground-state coherence generation and enable application of NMOR in detection of transient spin couplings.