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arXiv · 2602.07161

Two-photon-excited fluorescence spectroscopy of Rb atoms in a magneto-optical trap

Alan McLean·Christian Drago·Daniel Podos·Chengyi Luo·Caleb Brzezinski·Ting-Wei Hsu·John Sipe·Ralph Jimenez
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Abstract

We report the results of two-photon-excited fluorescence (TPEF) measurements of the $5\mathrm{S}_{1/2} \rightarrow 5\mathrm{D}_{5/2}$ transition of $^{85}$Rb and $^{87}$Rb cooled in a magneto-optical trap (MOT). We observe TPEF at excitation powers as low as 1 $\mu$W or fluxes as low as $2.98_{-0.94}^{+1.37} \times 10^{18}\ \text{photons}\,\text{cm}^{-2}\,\text{s}^{-1}$ ($^{85}$Rb) and $3.31_{-1.33}^{+2.21} \times 10^{18}\ \text{photons}\,\text{cm}^{-2}\,\text{s}^{-1}$ ($^{87}$Rb). Our results demonstrate that optically cooled Rb is a promising platform for observing sensitive two-photon spectral signatures at low photon fluxes.

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Alan McLean, Christian Drago, Daniel Podos, Chengyi Luo, Caleb Brzezinski, Ting-Wei Hsu, John Sipe, Ralph Jimenez. 2026-02-06. Two-photon-excited fluorescence spectroscopy of Rb atoms in a magneto-optical trap. https://doi.org/10.1103/c8gq-zp19

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