Abstract
Optical modulators are key building-blocks for high speed signal transmission and information processing. Current “complementary metal-oxide semiconductor” (CMOS) advanced fabrication tools allow for a dramatic reduction in device size to achieve large scale and cost effective integration. The work developed in this thesis is essentially focused on the design, fabrication and characterization of slow wave structures in order to realize compact and efficient modulators integrated on ultra-small silicon chips. This thesis consists of four main chapters as well as a concluding section on the work accomplished. Chapter one provides a short background on solid state physics and light propagation in high contrast integrated waveguides in order to give basic tools for understanding the underlying physics behind silicon electro-optical modulator operation. Chapter two introduces the main parameters of electro-optical modulators and is followed by a description of the main physical mechanisms that may be used for optical modulation in silicon. The state-of-the-art of silicon and silicon-based modulators is also provided. Additionally, the passive and active characterization techniques and setups are presented. Chapter three is devoted to the design, fabrication and characterization of an ultra-fast and compact slow wave, plasma dispersion-based silicon electro-optical modulator. Chapter four is dedicated to the design, characterization and fabrication of a novel type of engineered silicon slow wave waveguide exhibiting a high group index over a wide wavelength range. Potential applications of such a waveguide for wavelength-division-multiplexing (WDM) high speed modulation are explored. Finally, conclusions on the work realized are provided in Chapter five.