Probing strong light-matter interactions in organic molecular crystals using nonlinear optical techniques.

摘要

There are three related topics in this thesis. First, the theoretical and experimental aspects of the generation and detection of acoustic waveguide modes (Lamb waves) in ultrathin anthracene crystals using the transient grating technique is presented. This work can be used to determine the acoustic dispersion and the nature of Lamb waves in an anisotropic medium. It can also be used for nondestructive characterization of such properties as the elastic constants, the density and the thickness of ultrathin materials. Second, the dynamics of waveguide polaritons, which are the normal modes of a pure, finite molecular crystal with strong light-matter interactions, are explored at 298 K and at 1.5 K in anthracene, again using transient grating techniques. At 298 K, the diffusion constant for polaritons D