We theoretically and experimentally investigate a novel modulation concept on silicon (Si) based on the combination of quantum confinement and plasmon enhancement effects. We experimentally study the suitability of Ge/SiGe quantum wells (QWs) on Si as the active material for a plasmon-enhanced optical modulator. We demonstrate that in QW structures absorption and modulation of light with transverse magnetic (TM) polarization are greatly enhanced due to favorable selection rules. Later, we theoretically study the plasmon propagation at the metal-Ge/SiGe QW interface. We design a novel Ge/SiGe QW structure that allows maximized overlap between the plasmonic mode and the underlying Ge/SiGe QWs.

Under the FP7 HELIOS project a 16 channel 10G transceiver based on a separate integrated transmitter incorporating hybrid lasers and modulators on silicon and a separate receiver both for 1550nm wavelength range has been demonstrated. An MZM (ITLMZ) chip consisting of a single mode hybrid III-V/silicon laser, a silicon Mach-Zehnder (MZ) modulator and an optical output coupler exhibited 10G operation with high BER. A 200GHz 16 channel receiver with polarization management was obtained with a 2D grating coupler, 2xAWGs and 16 Ge photodiodes. Polarization Dispersion Loss (PDL) was below 1dB, Bandwidth (BW) above 20GHz, receiver sensitivity in the order of 0.08 A/W

Electroabsorption spectroscopy of well-identified index-defined semiconducting carbon nanotubes is reported. The measurement of high definition electroabsorption spectra allows direct indexation with unique nanotube chirality. Results show that at least for a limited range of diameters, electroabsorption is directly proportional to the exciton binding energy of nanotubes. Electroabsorption is a powerful technique which directly probes into carbon nanotube excitonic states, and may become a useful tool for in situ study of excitons in future nanotube-based photonic devices such as electroabsorption modulators.