Measurement of hyperfine constants and the isotope shift of rubidium 5P$_{1/2}$ excited-state using Saturated Absorption Spectroscopy

TL;DR

This study uses Saturated Absorption Spectroscopy with a homemade laser to precisely measure hyperfine constants and isotope shifts in rubidium's excited state, achieving high accuracy through linearized frequency calibration.

Contribution

It introduces a fully automated SAS setup with a confocal Fabry-Perot cavity for accurate hyperfine and isotope shift measurements in rubidium.

Findings

Measured hyperfine constants for $^{85}Rb$ and $^{87}Rb$ with high precision.

Established a linearized frequency axis for improved spectral accuracy.

Reported specific values for magnetic dipole coupling constants.

Abstract

The Saturated Absorption Spectroscopy (SAS) was performed to measure the hyperfine energy splittings of rubidium 5P$_{1/2}$ excited state using a homemade external-cavity diode laser (ECDL) operating at 795 nm. Any nonlinearities associated with ECDL scans were removed by using a low-expansion confocal Fabry-Perot cavity and hence created a linearized frequency axis for the spectra collected in a fully automated fashion. We report our measurements for the magnetic dipole coupling constants 120.79(29) and 407.75(50) for $^{85}Rb$ and $^{87}Rb$ respectively.