Persistent spectral antiholes, which correspond to increased absorption at the laser frequency, have been burned in an inhomogeneously broadened vibrational mode of Re${\mathrm{O}}_4^{-}$ embedded in alkali halide host lattices. A new model is proposed to explain nonphotochemical hole and antihole burning.

• Received 17 August 1983

DOI:https://doi.org/10.1103/PhysRevLett.52.303