# Photonics

(This project is finished.)

Photonics is to photons what electronics is to electrons. The main aim of photonics is to guide light on the nanoscale. This can be achieved by propagating light in nanostructured materials. These materials are refered to as Photonic Crystals and one can simulate the propagation of light in these structures using numerical methods. Based on these calculation one can used well-approved methods for the optimization of certain properties of Photonic Crystals.

In recent years, metals have entered the field of photonics. Often metal nanoparticles are embedded in an dielectric environment. The conduction electrons of the metal respond to external electrical fields. Such structures are called plasmonic structures. The research in this area is summarized under the name plasmonics.

The reaction of the conduction electrons to electrical fields may yield a locally strongly enhanced field. These enhanced fields are confined to the metal-dielectric interface and are the basis of e.g. the surface enhanced raman scattering. But there are also other effects possible. In collarboration with the Optics workgroup we calculate the field enhancements for spherical silver nanoparticles in glas in order to explain the deformation of such particles when irriated by laser light. Methods used include the Finite Element Method (FEM) and the Discrete Dipole Approximation.