Abstract
The existence of hole burning and the degree of homogeneity in the 4F3/24I11/2 laser transition of Nd3+ in a silicate glass at 295 K are established by exciting the small thermal population in the 4I11/2 state with a pulsed Nd : YAG laser and observing resonant fluorescence line narrowing. Measurements of time‐resolved line‐narrowed 4F3/24I9/2 spectra show that hole filling is slow; cross relaxation rates between ions in spectrally different sites are 4 s−1 for concentrations of ⩽3 wt.% Nd2O3.