Waveguides and modulators in 3C-SiC

We have designed and fabricated waveguide optical modulators using cubic silicon carbide-(3C-SiC)-on-insulator rib waveguides. A refractive index change is induced in the rib via the plasma dispersion effect. These types of devices have potential for relatively high-speed silicon-based photonics compatible with silicon processing technology, as compared to pure silicon. Furthermore, the wide bandgap (2.2 eV) of 3C-SiC makes the devices suitable for use over the visible and near infrared spectrum range as well as the longer communication wavelengths. We have demonstrated waveguiding in 3C-SiC, fabricating the waveguides by ion implantation of oxygen into a silicon carbide layer. We have also established a processing recipe for the SiC wafers which enables fabrication of 3-dimensional devices. The work reported here describes the fabrication of the devices and presents preliminary experimental results for the waveguide losses and the modulation of the refractive index as a:function of applied current. An efficient waveguide modulator for a single polarisation is reported.