A study of excited state dynamics of rare earth ions in solids by coherent transients and spectral holeburning

Barriers to spectral resolution imposed by instrumental limits and inhomogeneous broadening can often be removed by linear and nonlinear laser spectroscopy. This is illustrated by the case of LaF3+. Six orders of magnitude increase in resolution has been demonstrated, and this uncovered new mechanisms for optical dephasing such as coupling to nuclear spin fluctuations. The importance of the time-scale of the experimental probe is stressed, and the information obtained from spectral holeburning and coherent transients can be very different. This was found in CaF2+ where the fluorine nuclear spin-flips exhibit a wide range of time-scales. © 1988.