Anna Krylov of the University of Southern California is supported by an award from the Chemical Theory, Models and Computational Chemistry program in the Chemistry Division to develop theoretical methods and robust computational tools for modeling non-linear optical (NLO) properties. The CISE/ACI CIF21 Venture Fund for Software Reuse and the Computational and Data-Enabled Science and Engineering (CDS&E) have also contributed to funding this award. Krylov and her research group are developing formalisms and implementing computational methods to compute electronic factors for two-photon absorption (2PA) within the coupled-cluster (CC) and equation-of-motion (EOM) family of methods. These developments extend the robust and accurate EOM-CC methodology to describe EOM properties. To enable applications to realistic systems (20-30 atoms, ~1000 basis functions), they capitalize on recent methodological, computational and software developments. To include the effect of the environment (e.g., protein, solvent, molecular solid) on NLO properties, they employ the Effective Fragment Potential. Krylov and coworkers are applying these new computational tools to interrogate factors determining 2PA brightness of chromophores of fluorescent proteins used for in vivo imaging.
This research promotes fundamental understanding of non-linear processes that are exploited in novel spectroscopic approaches and technology. The computer codes developed in the framework of this research, which will be widely available to the research community, can used to design better fluorescent labels for using in bioimaging to study cellular processes in live systems, photodynamic therapy, and biosensors. These tools can also be used for developing NLO materials for micro-fabrication, 3D optical data storage and nanolithography, ultra-fast electro-optic modulation and switching, and a variety of other novel nano-bio-photonics applications.
