Detailed look at aspects of optical pumping in sodium

Abstract

Calculations and measurements are presented of the increase in F\ifmmode\bar\else\textasciimacron\fi{}=1 ground-state population as a function of incident laser intensity in optically pumped sodium. The calculations involve numerical integration of a multilevel version of the optical Bloch equations. Agreement between experiment and theory is good when proper account is taken of the residual Doppler width in the atomic beam, which causes a larger increase in the F\ifmmode\bar\else\textasciimacron\fi{}=1 population. The F\ifmmode\bar\else\textasciimacron\fi{}=1 population increases by 3.5% at 35 mW/${\mathrm{cm}}^{2}$, the highest laser intensity investigated.