Nano- and fermosecond laser pulses at 355 and 768 nm cause purely green single- and two-photon-excited interband emission in thin film US on glass at room temperature. It is demonstrated that both emissions occur according to the detailed balance principle and that the spectral shape of the emission is independent of the mode of excitation. The work also addresses energy dissipation in thin film US excited beyond the Mott-transition. (C) 2003 Elsevier B.V. All rights reserved.