Abstract

The nature of inhomogeneous broadening in rare earth doped crystals plays an important role in holeburning and dynamical optical properties of ions in solids. A previous measurement^[1,2] of the NQR linewidth variations of the Pr³⁺ ground state hyperfine levels as a function of offset from the optical line center of the ²H₄(Γ1)-¹D₂(Γ1) transition was made on a 0.5% Pr³⁺: LaF₃ sample (Fig. 1b) by using a Stark Modulated Optical Pumping (SMOP) holebuming technique.^[3] This measurement revealed a linear increase in the inhomogeneous broadening of the Pr³⁺ hyperfine transitions relative to the NQR width at the optical line center. No significant shift in the NQR central frequency was observed. Similar trends of increased quadrupole broadening in the wings of the optical line are reported here for concentrations of 0.1% and 1.0% Pr³⁺(Fig. 1c).The NQR hyperfine linewidth measured at the center of the inhomogeneous optical line is observed to increase with the Pr³⁺ concentration. We find the ³H₄(Γ1)-¹D₂(Γ1) inhomogeneous optical line shifts to lower frequencies as the Pr³⁺ concentration is increased from 0.1% to 1.0% (Fig. 2).

© 1992 IQEC