Bleaching of the photoluminescence of the 3H optical center by ultra-violet or intense blue laser light was observed, accompanied by enhancement of the TR12 center luminescence in type-IIa monocrystalline diamond and polycrystalline chemical vapour deposited diamond. The characteristic times of photoluminescence bleaching and enhancement processes were measured at different excitation photon energies and temperatures. No direct correlation between these processes was found. A H-related model for the 3H defect was proposed that could explain the bleaching effect and other properties of the 3H center.

Laser-Induced Transformation of 3H Defects in Diamond. I.I.Vlasov, V.G.Ralchenko, E.Goovaerts: Physica Status Solidi A, 2002, 193[3], 489-93