Modeling rubidium optical pumping in the intermediate buffer-gas-pressure regime

E. V. Kulagin, Nadejda Eremina, A. I. Pikhtelev +1 more

E. V. Kulagin, N. M. Eremina, A. I. Pikhtelev +1 more

Fernand D. Bedard

Mark Rosenberry, J. Paxon Reyes, D. Tupa +1 more

We have made a systematic study of rubidium optical pumping in a simple cylindrical cell geometry with a high-power $10\phantom{\rule{0.3em}{0ex}}\mathrm{W}$ diode laser array, low magnetic fields, and buffer-gas pressures of less than $50\phantom{\rule{0.3em}{0ex}}\text{torr}$. We have determined rubidium polarizations experimentally for ${\mathrm{H}}_{2}$, ${\mathrm{N}}_{2}$, He, and Ar buffer gases, with Rb number densities from ${10}^{12}\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}{10}^{13}\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$. Comparison to a relatively simple optical pumping model allows us to extract useful information about radiation trapping and quenching effects.

Roy Zektzer, Eliran Talker, Noa Mazurski +2 more

We experimentally demonstrate chip-scale optical pumping of Rubidium vapor based on novel atomic-cladded tapered nano-waveguides with different buffer-gas pressures. Precise control over the interaction volume and coupling enables the optimization of the atomic polarization.

Stavros Christopoulos, Peter Moroshkin, Lars Weller +5 more

Abstract Optical spectroscopy of atoms and molecules is a field where one usually operates very far from thermal equilibrium conditions. A prominent example is spectroscopy of thin vapors, where the pump irradiation leads to a non-equilibrium distribution within the electronic structure that is well shielded from the environment. Here we describe experimental work investigating absorption and emission lines of rubidium vapor subject to a noble buffer gas environment with pressure 100–200 bar, a regime interpolating between usual gas phase and liquid/solid state conditions. Frequent elastic collisions in the dense buffer gas sample cause a large coupling to the environment. We give a detailed account of recent observations of the Kennard–Stepanov scaling, a Boltzmann-like thermodynamic frequency scaling between absorption and emission profiles, for both atomic and molecular rubidium species in the gaseous environment. Our observations are interpreted as due to the thermalization of alkali-noble gas submanifolds in both ground and electronically excited states respectively. Both pressure broadening and shift of the high pressure buffer gas D -lines system are determined. We also discuss some prospects, including possible advances in collisional laser cooling and optical thermometry.