Silicon photonics based on Ge/SiGe quantum well structures

Recent advances in the theoretical and experimental studies of Ge/SiGe quantum wells structures will be presented with a focus on optical telecommunication applications. Firstly, high-speed stand-alone Ge/SiGe QW electro-absorption modulators and photodetectors will be reported. It will be followed by the presentation of different methods for engineering Ge/SiGe QW to tune the operating wavelength to 1.3 μm. Then the demonstration of a strong electro-refraction Ge/SiGe QW will be reported. This effect could be used to achieve optical modulation but requires the embedding of the QWs in a Mach-Zehnder interferometer. Finally it will be shown that these active devices can be combined with advanced passive structures using Ge-rich SiGe virtual substrate on graded buffer as a waveguide.