Theoretical calculation of saturated absorption spectroscopy of atomic ytterbium beam

Abstract

Saturated absorption spectroscopy is a technique of measuring the transmission of a probe beam induced by a counter-propagating pump beam, which can achieve a nearly Doppler-free spectral resolution. In this study, the saturated absorption spectra of individual isotopes of ytterbium atoms are calculated using rate equations for various polarizations of the probe and pump beams under an assumption that the distribution of velocities for atoms within the atomic beam is a Maxwell-Boltzmann distribution. The fourth-order Runge-Kutta method is used for calculation of the rate equations, then the absorption coefficient in the vicinity of the atomic transitions is calculated, and the transmission of the probe beam is obtained by Beer-Lambert law. We compare the calculations with an experimental result from the literature and obtain a good agreement.