Measurement of hyperfine structure in the ${\mathrm{D}}_1$ line of Rb

Abstract

We report a precise measurement of hyperfine constants in the ${\mathrm{D}}_1$ line ($5{\mathrm{P}}_{1/2}$ state) of the two stable isotopes of Rb. The motivation for the work is to try and resolve discrepant values that exists in the literature. We use a technique that is different from other methods---one where the laser is not locked to a particular transition but scanned around it. This is advantageous because it overcomes frequency shifts due to servo-loop errors and other sources of noise in the experiment. The values in the two isotopes are: $A=120.510(26)$ MHz in ${}^{85}\mathrm{Rb}$, and $A=408.340(19)$ MHz in ${}^{87}\mathrm{Rb}$. These values are at variance with earlier values reported from our lab, but consistent with other published measurements.

arXiv comment11 pages, 7 figures