In this work, we present and analyze the ability of periodic SubWavelength Grating waveguides to act as mode filters. Moreover, we exploit this ability to design a novel kind of Add/Drop Mode Division Multiplexer exhibiting an extinction ratio over 20dB in the whole C-Band.

Different technologies for the fabrication of Germanium photodetectors were developed. Germanium was grown by RPCVD in a silicon cavity in order to provide a direct coupling with a rib silicon waveguide. With direct deposition of Ti/TiN/AlCu on Ge, Metal-Schotkky-Metal (MSM) diodes were formed. PIN photodiode were fabricated either with in-situ doping during RP-CVD epitaxy of Ge, either by ion implantation. For vertical PIN photodiode, the germanium was successfully etched either in mesa either anisotropically with Cl 2 gazes. Small footprint Ge photodiodes can lead to high speed operation on CMOS.

Photonic metamaterials made of graded photonic crystals operating near the bandgap frequency region are proposed for field manipulation around λ=1.5µm. Proof-of-concept structures have been studied using Hamiltonian optics and FDTD simulation, fabricated, and characterized using farfield optical measurements. Experimental results are in good agreement with predictions, showing the interest of graded photonic crystals as an (ultra-low loss) alternative solution to the use of metamaterials combining dielectric and metallic materials with sub-wavelength unit cells.