Multi-channel fluorescence spectroscopy of the Rb 5 S 1 / 2 – 7 S 1 / 2 transition via monochromatic two-photon excitation
Year: 2025
Type: article
Abstract: Multi-channel fluorescence detection of alkali atoms offers a robust approach to overcome the intrinsically low transition probabilities of conventional single-wavelength spectroscopy and thus enhances the development of frequency standards. Here, we experimentally realize the multi-channel fluorescence spectroscopy of the Rb 5 S 1 / 2 – 7 S 1 / 2 monochromatic two-photon transition using a single 760 nm laser. Simultaneous fluorescence emissions at 780 nm, 741 nm, 795 nm, 728 nm, and approximately 420 nm are observed, consistent with the expected decay channels. The dependence of these fluorescence intensities on laser power, polarization, and vapor temperature is systematically investigated, revealing the evolution of atomic transitions under varying experimental conditions. Pressure broadening measurements of the Rb 5 S 1 / 2 – 7 S 1 / 2 transition yield a spectral linewidth of ∼ 1 . 08 ( 2 ) MHz. Compared with conventional single-wavelength detection at 420 nm, multi-channel approach significantly improves the signal-to-noise ratio and provides comprehensive insights into the atomic structure. These results establish a reliable foundation for developing optical frequency standards based on the Rb 5 S – 7 S transition. • Multi-channel fluorescence of Rb 5 S – 7 S transition using a single 760 nm laser. • Five fluorescence channels detected at 780, 741, 795, 728, and 420 nm. • Fluorescence depends on laser power, polarization, and vapor temperature. • Spectral linewidth of ∼ 1.08(2) MHz obtained via pressure broadening. • Multi-channel detection enhances SNR and aids optical frequency standards.
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,530
OpenAlex ID: W4416408960