Observation of Laser-Induced Fluorescence Line Narrowing in Glass: Nd

Laser-induced fluorescence line narrowing has been observed for the first time in a nonresonantly excited rare-earth system. Excitation with the 4727-{} A⁺ line into the ⁴G11/2 level of Nd³⁺ in glass results in narrowing of transitions from the ⁴F3/2 to both the ⁴I9/2 ground manifold and the ⁴I11/2 excited manifold. The concentration dependence of the line narrowing provides information regarding resonant ion-ion energy transfer within the inhomogeneously broadened system.