Photonic Material Design

Design of a Polymeric Material with a Large Nonlinear Optical Susceptibilities

General information

Background

More and more of information distribution is carried out by means of optical techniques. The driving force for this is primarily the progress within computer science and the development of local and global information networks. Optical techniques are the prerequisites for rapid computer communication systems, such as the "information super-highways" and "fibers-to-the-home". They demand less power and are less vulnerable to electro-magnetic disturbances than conventional electronic devices. The advent of powerful lasers has permitted transmission of optical information at very high speed, something which requires active photonic devices based on various nonlinear optical phenomena. There are good prospects to use computers to simulate and design molecular photonic and nonlinear optical materials. One can mention three areas for such computations; Designing and testing polymer materials based on ferroelectric liquid crystals; Intramolecular charge transfer molecules for optical limiting applications; Molecular systems with large polarizability anisotropy for photo-refractive applications.

Project description

The goal with this diploma work is to design a polymer with "good" nonlinear optical properties. A set of basic building blocks should be used and examined in different combinations; like phenyl- and thiophene rings for the polymer backbone, nitro-, amino- and methyl groups for substituents; dinitrogen-, ether-, and (poly)ethylene groups as bridges, to mention some important examples. The polymer is modeled by oligomers, that is by a limited set of the repeat units.

One task is to investigate the special role of charge transfer interaction for the nonlinear susceptibility. Another task is to see if better performance can be obtained by forming so-called guest-host systems, that is a covalent attachment of the nonlinear optical chromophore to a polymer backbone, or by forming copolymers, that is a double repeat unit.

Computations will be carried out for both second and third order nonlinear susceptibilities, using response theory in the quantum chemistry program Dalton and the Monolith massive parallel computer at the National Supercomputer Centre (NSC).

Sincerely,
Patrick Norman.

Last modified: Wed Feb 7 08:40:07 MET 2007