Time-resolved EPR study of spin polarization and dynamics of F+ centres in additively coloured CaO crystals

Abstract

Optical excitation of additively coloured CaO crystals generates ¹T_1u and ³T_1u excited states and F⁺ defects, the latter being revealed by EPR experiments. Interaction of the excited ³T_1u triplet state and the F⁺ centre is documented by the emissive character of the transient EPR signal detected just after a laser pulse. A quenching of the initial polarization, observed at high microwave power, is ascribed to microwave saturation of the F⁺ spin levels.