Circular dichroism in atomic vapors: magnetically induced transitions responsible for two distinct behaviors

Abstract

Atomic transitions of alkali metals for which the condition $F_e-F_g=\pm 2$ is satisfied have null probability in a zero magnetic field, while a giant increase can occur when an external field is applied. Such transitions, often referred to as magnetically-induced (MI) transitions, have received interest because their high probabilities in wide ranges of external magnetic fields which, in some cases, are even higher than that of usual atomic transitions. Previously, the following rule was established: the intensities of MI transitions with $\Delta F=\pm 2$ are maximum when using respectively ${\sigma }^{\pm }$ radiation. Within the same ground state, the difference in intensity for ${\sigma }^{+}$ and ${\sigma }^{-}$ radiations can be significant, leading to magnetically induced circular dichroism (MCD), referred to as type-1. Here, we show that even among the strongest MI transitions, $i.e$ originating from different ground states for ${\sigma }^{+}$ and ${\sigma }^{-}$, the probability of MI transition with $\Delta F=+2$ is always greater, which leads to another type of MCD. Our experiments are performed with a Cs-filled nanocell, where the laser is tuned around the D${}_2$ line; similar results are expected with other alkali metals. Theoretical calculations are in excellent agreement with the experimental measurements.

arXiv comment17 pages, 7 figures

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Cited by in corpus (6)

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• Wide range linear magnetometer based on a sub-microsized K vapor cell
• Coherent Optical Processes on Cs D${}_2$ line Magnetically Induced Transitions
• Sub-Doppler spectra of sodium $D$ lines in a wide range of magnetic field: theoretical study
• Strongest Magnetically Induced Transitions in Alkali Metal Atoms with nuclear spin $3/2$
• Formation of strongly shifted EIT resonances using "forbidden" transitions of Cesium