Coherent Dark States of Rubidium 87 in a Buffer Gas using Pulsed Laser Light

摘要

The coherent dark resonance between the hyperfine levels F=1, m=0 and F=2,m=0 of the rubidium ground state has been observed experimentally with thelight of a pulsed mode-locked diode laser operating at the D1 transitionfrequency. The resonance occurs whenever the pulse repetition frequency matchesan integer fraction of the rubidium 87 ground state hyperfine splitting of 6.8GHz. Spectra have been taken by varying the pulse repetition frequency. Usingcells with argon as a buffer gas a linewidth as narrow as 149 Hz was obtained.The rubidium ground state decoherence cross section 1.1*10^(-18) cm^2 forcollisions with xenon atoms has been measured for the first time with thismethod using a pure isotope rubidium vapor cell and xenon as a buffer gas.