Abstract

The irradiation of an absorbing medium will, by thermalization of the excited state energy, eventually heat the medium. In case of a chain of thermalization steps, the first one including only subsets of the molecule states, the formation of the intermediate partial thermal equilibrium may release or withdraw translational energy from the medium. In this paper, we show that in a setup with laser beams generating a grating in oxygen, the size and sign of the heat transfer for the formation of a transient rotational state thermal equilibrium can be determined from the temporal evolution of the generated superposed population, thermal, and electrostrictive grating.

© 1998 IEEE