Optical detection of magnetic resonance in the vibronic sidebands of R and N lines in MgO:Cr3+

Abstract
Measurements of ODMR in the excited states of Cr3+ ions in cubic and tetragonal sites in MgO have been used to elucidate the nature of the vibronic sidebands. A comparison of the experimental spectra for zero-phonon line and vibronic sideband with the theoretically calculated selection rules shows that interaction with T2u odd-parity modes of vibration is the dominant interaction giving rise to the vibronic sidebands.