Measurement of the cesium 7d 2D 3/2 hyperfine coupling constants in a thermal beam using two-photon fluorescence spectroscopy

Abstract

The hyperfine intervals of the 133Cs 7d 2D 3/2 manifold are measured using two-photon resonant laser-induced- fluorescence of an effusive cesium beam. A radio-frequency phase modulation technique directly references the relative frequency scale to the ground hyperfine splitting of 87Rb. The 133Cs 7d 2D3/2 hyperfine intervals are used to generate the magnetic dipole coupling constant A=7.36 0.03 MHz and electric quadrupole coupling constant B=−0.1 0.2 MHz. The A coupling constant agrees with a previous measurement, but with an improvement in resolution that is sufficient to serve as a benchmark value for testing high-precision theory. The result for the B coupling constant is the first constraint placed on this parameter.