The dynamics of resonant cross relaxation between different electron-spin species, viz., the ${F_2}^{2+}\mathrm{}(S=1\mathrm{})\mathrm{}$ and $F^{+}(S=\frac{1}{2})$ defects in CaO, is studied by optical-spin-echo spectroscopy. For the ${F_2}^{2+}$ center in the photoexcited ${}_{}{}^3{}_{}{}^{}B_1^{}{}_{}{}^{}$ state, the phenomenon of hole burning by resonant cross relaxation is inferred.

• Received 30 March 1982

DOI:https://doi.org/10.1103/PhysRevB.26.427