Experimental test of the optical bloch equations for solids

This paper provides the first experimental test of the Bloch equations for an optical transition in a low-temperature impurity-ion solid, Pr3+: LaF3, where the condition T1T2 applies. Intensity-dependent optical free-induction-decay measurements are performed by use of an ultrastable cw dye laser (linewidth, 300 Hz) and reveal an exp(-2tT2) decay law at low Rabi frequency (‡), as predicted by the Bloch equations, and an exp(-t) decay at high, which violates the Bloch prediction but agrees with Redfield's characterization of NMR saturation in solids. © 1983 The American Physical Society.