Measurement of Sodium Vapor Densities in Optical Pumping Experiments using a Scanning Fabry–Perot Interferometer*

Abstract

Reliable estimates of alkali vapor densities in the absorption cells used in optical pumping experiments have usually been quite difficult to obtain. In the present work, a pressure-scanned Fabry–Perot etalon has been used as a high-resolution device to obtain absorption profiles from which the alkali vapor density can be directly derived. The measurements have been made with sodium only, and the results of these experiments are graphs of the optical-pumping signal strength in a Dehmelt transmission arrangement as a function of the alkali vapor density. These graphs may be useful in estimating vapor densities in those optical-pumping experiments for which construction of the requisite spectroscopic equipment is not feasible.