Silicon photonics presents a number of attractive characteristics for applications ranging from microwave photonics to chemical sensing to microprocessor interconnects. Silicon exhibits low loss at wavelengths near 1.5 microns, which makes it simple to leverage existing telecommunications components. In addition, the fabrication and manufacture of silicon photonics is typically compatible with CMOS-based silicon processing. Finally, the large-scale integration of photonic components on a silicon chip will enable a wide range of increasingly complex devices and systems.
Our research is focused on the use of micro- and nanomachining techniques to fabricate state-of-the-art integrated waveguide structures, such as Fabry-Perot microcavities and add-drop filters, in a silicon-on-insulator (SOI) system. These techniques can be used to fabricate high-index-contrast DBR mirrors which can be over 99% reflective over bandwidths spanning >100 nanometers. Selective etching can also be used to release the silicon waveguides, enabling the integration of micro-electro-mechanical structures with photonic devices on a single chip. These simple fabrication techniques enable a large variety of devices spanning a broad range of application areas.
Research in the general area of silicon photonics includes:
- Integrated waveguide Fabry-Perot microcavities with high index contrast silicon/air grating mirrors
- Tunable filters using the thermo-optic effect or micro-electro-mechanical systems (MEMS)
- Mode-conversion cavity (MCC) add-drop filters that rely on mode separation via asymmetric gratings and Y-branch waveguides
- Linearly cascaded Fabry-Perot microcavities for increased extinction and lineshape tailoring
- Multimode optoelectronic oscillators coupled to Fabry-Perot microcavities for low-power RF signal detection
- Optical-micro-electro-mechanical (Optical MEMS) chemical sensors based on chemo-selective analyte sorption and mass-loading
- Optical phased arrays for non-mechanical beam steering