Sub-doppler nuclear detection of laser-induced orientation of sup 85 Rb sup m

Using laser-induced nuclear-orientation and optical-saturation techniques, we have produced sub-Doppler changes in the anisotropy of the angular distribution of the 514-keV {gamma} rays from the 1-{mu}s isomer {sup 85}Rb{sup {ital m}}. This permits high-resolution measurements of {ital D}1 and {ital D}2 hyperfine transitions of atoms of the isomer, which give the isomer's nuclear electric quadrupole moment, {minus}0.73{plus minus}0.17 b, and its nuclear magnetic dipole moment, (6.043{plus minus}0.005){mu}{sub {ital N}}. The isomer shift, {minus}113{plus minus}8 MHz relative to the ground state of {sup 85}Rb, corresponds to a change in the mean-square charge radius of +0.174{plus minus}0.008 fm{sup 2}.