Two-photon excitation of rubidium atoms inside porous glass

Abstract

We study the two-photon laser excitation to the 5D${}_{5/2}$ energy level of ${}^{85}$Rb atoms contained in the interstices of a porous material made from sintered ground glass with typical pore dimensions in the 10 - 100 $\mu$m range. The excitation spectra show unusual flat-top lineshapes which are shown to be the consequence of wave-vector randomization of the laser light in the porous material. For large atomic densities, the spectra are affected by radiation trapping around the D2 transitions. The effect of the transient atomic response limited by time of flight between pores walls appears to have a minor influence in the excitation spectra. It is however revealed by the shortening of the temporal evolution of the emitted blue light following a sudden switch-off of the laser excitation.

arXiv comment7 pages, 4 figures, regular article

References in corpus (7)

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• Disordered, strongly scattering porous materials as miniature multipass gas cells
• Lifetime measurements of the 5d states of rubidium
• Three dimensional confinement of vapor in nanostructures for sub-Doppler optical resolution
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• Rb optical resonance inside a random porous medium
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