Electron spin resonance of NV-=SUP=-(-)-=/SUP=--centers in synthetic fluorescent diamond microcrystals under conditions of optical spin polarization

Electron paramagnetic resonance (EPR) spectra of synthetic diamond microcrystals with NV (-) -centers have been studied. It is shown that under the conditions irradiation material light a xenon lamp at low temperatures ~ 100 K, intensities EPR signals corresponding to "forbidden" (Delta m s =2) and field allowed =1) transitions are amplified several times, while from nitrogen impurity nickel in charge state -1 practically do not change. This due change population levels ground triplet - center optical polarization spins =0 level. Keywords: nitrogen-vacancy centers, diamond, electron resonance, spin polarization, luminescence.