This PhD thesis describes the realization of integrated optical components in Silicon-on-Insulator (SOI) material. In particular, the thesis is focused on the realization of Mach-Zehnder delay interferometers (MZ-DI) in 4um SOI technology. As an example, the ability of MZ-DI for the demodulation of phase-modulated data signals is investigated. The thesis considers in detail the design of the basic components for the realization of MZ-DIs in SOI technology. These components are single-mode waveguides and multi-mode interference (MMI) couplers. Following simulations and iterations of the...