KTH Applied Physics seminars

Optical materials - waveguides and more

by Prof. Ursula Gibson (NTNU in Trondheim)

Europe/Stockholm
Albanova, FA31

Albanova, FA31

Description
This talk will contain an introduction to some of the optical materials with which I have worked, including protein crystals, photonic crystals and photovoltaic nanomaterials. This introduction will be followed by a more in-depth discussion of two recently initiated projects with some ideas for future work. Silicon-core fiber waveguides for the near-IR (>1.5 micron) have been made using interface modifiers that reduce stress during the cooldown process and will permit inclusion of active species at the interface between the silicon and the silica cladding. Transition-metal doped ZnS films are being made using dopants such as Cr and Fe. While Cr predominantly acts as a dopant, there are reports that Fe can be used both in this role, and to change the overall bandgap of an alloyed film at higher concentrations. We recently produced our first thick Cr-doped films, and will be investigating their optical properties in the near future.