ODMR of recombination centres in crystalline quartz

Abstract
The well known 2.8 eV luminescence band in quartz has been studied using optically detected magnetic resonance (ODMR). A triplet state with a very large fine-structure splitting is found to contribute to the emission. The principle axes of the triplet are identified. The possibility that the luminescence originates in the decay of a self-trapped exciton involving a transient oxygen Frenkel pair is discussed.