Silicon oxynitride planar waveguiding structures for application in optical communication

The refractive index of silicon oxynitride (SiON), a widely used material for integrated optics devices, can be chosen in a wide range between 1.45–2.0. We describe how the consequent large design freedom can be exploited on the one hand for a “standard‿ polarization independent optical channel waveguide having a favorable tradeoff between efficient fiberchip coupling and small bend radii (compact devices) and on the other hand for special-purpose and hybrid components where the refractive index should be finely adjusted for obtaining the desired functionality. We illustrate the applicability of SiON by describing a few devices for optical filtering in a new architecture for wavelength multiplexing, modulation, polarization splitting and second-harmonic generation.