Observation of Magnetically-Induced atomic transitions of the Cs 6S$_{1/2} \rightarrow 7$P$_{3/2}$ line at 456 nm

Abstract

It has recently been demonstrated that magnetically induced (MI) transitions, a class of transitions forbidden at zero magnetic field, of the Cs 6$^2$S$_{1/2} \rightarrow 6^2$P$_{3/2}$ (D$_2$) line, exhibit promising features for high-resolution physics applications in the near-infrared range. In this work, we study a group of seven MI transitions ($F_g = 3 \rightarrow F_e = 5$) of the Cs $6^2$S$_{1/2} \rightarrow 7^2$P$_{3/2}$ line at $\lambda = 456$ nm. The experimental measurements are in very good agreement with theoretical predictions based on the diagonalization of the Zeeman Hamiltonian. In magnetic fields ranging from $0.2-3$ kG, these transitions reach a maximum intensity above that of conventional transitions. Another noteworthy property is their large frequency shift, reaching approximately $17~\mathrm{GHz}$ with respect to the unperturbed hyperfine transitions in magnetic fields of about $3~\mathrm{kG}$. These interesting properties may prove useful for the realization of optical frequency references or magnetometers with sub-micron spatial resolution in the blue region of the spectrum.