Measuring the hyperfine splitting of rubidium 5P$_{1/2}$ excited-state using Saturated Absorption Spectroscopy

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. Our results will be compared with the previous measurements reported in the literature.