Spectral hole burning is observed for the OH stretching mode of HDO dissolved in ${\mathrm{D}}_2$O at 298 K after intense infrared excitation. Three spectral components are inferred from the transient band shapes and related to an icelike molecular environment and other hydrogen-bonding configurations. A population lifetime of ${\mathit{T}}_1$=8±2 ps and an anharmonic frequency shift of 270±20 ${\mathrm{cm}}^{\mathrm{-}1}$ are measured.

• Received 19 October 1990

DOI:https://doi.org/10.1103/PhysRevLett.66.2092