Persistent Antiholes in the Vibrational Spectra of Matrix-Isolated Molecules

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.