All-optical measurement of Rydberg-state lifetimes

Abstract

We have developed an all-optical method for measuring the lifetimes of $nS$ and $nD$ Rydberg states and demonstrate its capabilities with measurements on a dilute cloud of ultracold $^{87}\mathrm{Rb}$ atoms in a cryogenic environment. The method is based on the time-resolved observation of resonant light absorption by ground-state atoms and selective transfer of Rydberg atoms into the ground state at varying delay times in order to reconstruct Rydberg decay curves. Our measurements of the $^{87}\mathrm{Rb}$ $30{S}_{1/2}$ state indicate an increase of the lifetime at lowered environment temperatures, as expected due to decreased blackbody radiation. For the $38{D}_{5/2}$ state with an attractive dipole-dipole interaction, ionization and lifetime reduction due to collisional effects are observed.