Laser & Optoelectronics Progress, Volume. 62, Issue 5, 0530003(2025)
Spectroscopy Technique for Hyperfine Energy Level Transition of Atomic Excited States
In a 133Cs 6S1/2→6P3/2→6D5/2 (852 nm+917 nm) ladder-type atomic system, atoms are populated on the 6D5/2 excited state from the 6S1/2 ground state via step-wise excitation using two lasers with wavelengths of 852 nm and 917 nm. Subsequently, 456 nm fluorescence photons are emitted via spontaneous decay in the 7P3/2→6S1/2 transition. Thus, spectral signals between the hyperfine transition of excited states, i.e., 6P3/2F'=5→6D5/2F″=6, is obtained by detecting 456 nm fluorescence photons. Atomic excited-state spectroscopy via fluorescence detection, abbreviated as AESVFD (atomic excited-state spectroscopy via fluorescence detection) herein, is demonstrated in this study. The characteristics of AESVFD with counter-propagating (CTP) and co-propagating (CP) configurations were compared when 852 nm and 917 nm laser beams were passing through the cesium vapor cell of the spectroscopy system. Experimental results show that AESVFD in the CTP configuration yields a significantly higher signal-to-noise ratio (SNR) and a narrower spectral linewidth than that in the CP configuration, which is due to the quantum coherent effect in the ladder-type atomic system. The dependencies of AESVFD on experimental parameters such as the atomic-vapor temperature, polarization, and power and frequency detuning of the pump lasers were systematically measured. Subsequently, the optimized experimental conditions for obtaining narrow linewidths and high SNRs via AESVFD were analyzed. The narrowest linewidth obtained via AESVFD is less than 5.0 MHz, which is similar to the natural linewidth of the 6P3/2 excited state at 5.2 MHz. Investigating precision spectroscopy is crucial for the further examination of atomic energy-level structures and for testing theoretical atomic models.
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Lanlan Zheng, Baodong Yang, Junli Bai, Haitao Zhou. Spectroscopy Technique for Hyperfine Energy Level Transition of Atomic Excited States[J]. Laser & Optoelectronics Progress, 2025, 62(5): 0530003
Category: Spectroscopy
Received: Jul. 2, 2024
Accepted: Aug. 29, 2024
Published Online: Mar. 10, 2025
The Author Email: Yang Baodong (ybd@sxu.edu.cn)