Abstract

It has been well established that for many metastable electronic levels of impurity ions in insulators, optical coherence times at liquid helium temperatures are limited by magnetic interactions with host nuclear spins.¹ To understand coherence loss in detail, one needs measurements of optical and spin dephasing, magnetic properties and hyperfine structure of impurity ions, and spin dynamics of host nuclei. To this end techniques such as spectral hole burning,² coherent transients (e.g. photon echo),^1,3 and optical-rf double resonance⁴ have been used. All of these are limited directly or indirectly by optical T₂, and have not directly probed the dynamics of host nuclei.

© 1984 Optical Society of America