First-principle quantum modeling of optical power limiting materials

We highlight the course of development of a project initiated 1998 by the authors and concerned with quantum modeling of optical power limiting materials. The methodological development has involved various quantum mechanical technologies for a description of multi-photon excitations within the framework of wave function and density function theories, with relativistic effects being addressed at rigorous as well as more approximate levels of theory. The method development has also involved models for vibronic and solvent contributions to the multi-photon excitations as well as pulse propagation based on the solution of the classical wave equations. Our review of these issues is completely nonmathematical. Results from sample applications are discussed in order to illustrate different aspects of concern for choosing materials with good optical limiting capabilities. Some focus is given to organic and organometallic push-pull compounds, including metallo-porphyrin compounds and platinum complexes.