Laser Induced Shape Transformation Of Silver Nanoparticles Embedded In Glass

Glasses containing metallic nanoparticles show very promising linear and nonlinear optical properties, mainly due to the surface plasmon resonance (SPR) of the nanoparticles. Spectral position (in the visible and near-infrared range) and polarization dependence of the SPR are, besides other parameters, characteristically determined by the nanoparticles' shapes. In this context, laser-based techniques to modify the shape of the metal particles are of great interest since they provide a very powerful and flexible tool to control and optimize the optical properties of these materials. This thesis considers aspects of interactions of intense fs laser pulses with silver nanoparticles incorporated in soda-lime glass; and reveals new information concerning the processes arising by excitation of the silver nanoparticles by the laser pulses and leading to structural alterations. The studies presented in the thesis aim to understand in details the mechanism of NP shape transformation, as well as, to optimize the technique of laser-induced modification of the optical properties of composite materials with metal nanoparticles for production of (sub-) micron structures with high polarization contrast and very broad tunable range of dichroism; that, in turn, will allow this technique to be used for many applications.