# Single-photon cesium Rydberg excitation spectroscopy using 318.6-nm UV laser and room-temperature vapor cell

## TL;DR

This paper demonstrates single-photon Rydberg excitation spectroscopy of cesium atoms in a room-temperature vapor cell using a 318.6 nm UV laser, revealing velocity-selective spectra and enabling laser frequency stabilization.

## Contribution

It introduces a direct single-photon excitation method to Rydberg states in cesium vapor at room temperature, providing new spectral data and a potential frequency reference.

## Key findings

- Observed velocity-selective Rydberg spectra.
- Determined quantum defect as 3.56671(42).
- Achieved laser frequency stabilization using demodulated spectra.

## Abstract

We demonstrate a single-photon Rydberg excitation spectroscopy of cesium (Cs) atoms in a room-temperature vapor cell. Cs atoms are excited directly from 6S1/2 ground state to nP3/2 (n = 70 - 100) Rydberg states with a 318.6 nm ultraviolet (UV) laser,and Rydberg excitation spectra are obtained by transmission enhancement of a probe beam resonant to Cs 6S1/2, F = 4 - 6P3/2, F' = 5 transition as partial population on F = 4 ground state are transferred to Rydberg state .Analysis reveals that the observed spectra are velocity-selective spectroscopy of Rydberg state, from which the amplitude and linewidth influenced by lasers'Rabi frequency have been investigated. Fitting to energies of Cs nP3/2 (n = 70 -100) states, the determined quantum defect is 3.56671(42). The demodulated spectra can also be employed as frequency references to stabilize the UV laser frequency to specific Cs Rydberg transition.

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Source: https://tomesphere.com/paper/1706.06237