Projects

On-chip nonclassical light sources
Armand, Konstantinos, Tomas, Kai, Kevin
Quantum information processing and cavity QED with quantum dots in photonic crystal nanocavities
Armand, Konstantinos, Tomas, Kai, Kevin
Nanometallic cavities
Yousif, Kevin, Tom, Tomas
Silicon Carbide photonics
Tom, Kai, Marina
Electrically injected nanocavity lasers and modulators
Jan
Silicon Germanium photonics
Jan
Nonlinear optics in nanophotonic structures
Sonia, Marina, Linda
Nanophotonic devices for biomedical applications
Alex, Jan
Objective-First Design for Nanophotonics
Alex
Videos of our research

Group IV photonics

A germanium microdisk side coupled to a fiber taper

Germanium pseudo-heterostructure, showing carrier localization in the nanowire

The Goal:

Reasons:

Challenges

Germanium is an indirect band gap semiconductor, and as such it is ordinarily a poor optical emitter. However, the indirect band edge is only 0.165 eV below the direct band edge, and this offset can be decreased or even reversed by applying a sufficient tensile strain. Furthermore, even with indirect-gap Ge, n-type doping can be used to fill up states in the indirect valley and make the material quasi-direct-gap. Finding suitable fabrication methods to heavily strain and dope germanium while integrating high-Q optical cavities, minimizing non-radiative recombination, and avoiding free carrier absorption can be difficult, and we are exploring this area in order to address these issues.

Achievements

Cavity-enhanced emission from highly-strained Ge

last modified on Saturday August 01, 2015