Spectral hole burning and Raman heterodyne signals associated with an avoided crossing in the NV centre in diamond

The nitrogen-vacancy centre in diamond exhibits an avoided crossing of grou nd state electron spin levels in a magnetic field of similar to 1028 G appl ied along the [1 1 1] direction. In this paper, the magnetic field dependen ce of Raman heterodyne signals and the optical transmission at 638 nm in th e vicinity of the avoided crossing are reported. It is discussed that the o ptically induced spin polarization of ground state populations produces ano malous fine structure hole-burning behaviour. (C) 2000 Elsevier Science B.V . All rights reserved.