On-Chip Devices based on III-V Semiconductors
Group III-V semiconductors have seen increased interest in recent years as they allow for the precise engineering of their optical properties through the control of their constituent elements. In addition, many III-V compounds form direct-bandgap semiconductors. Consequently, they are suitable for the development of photonic devices and integrated circuits that require a monolithic design approach.
In contrast to the popular silicon-on-insulator platform for photonics, laser and photodetector co-integration are more easily achieved with III-V materials. Our group has extensive clean-room experience in the fabrication of high-quality III-V semiconductor integrated photonic devices. Significant attention has been devoted to Indium Phosphide (InP), one of the most commercialized semiconductor materials for photonics. Recent work from our group investigated methods for eliminating Indium Chloride needle formation on InP platforms to produce low-loss InP photonic circuits.
Here are some before/after images showing the effect of InCl needle elimination to make low-loss InP-based waveguides.
In addition to having extensive experience in device fabrication, our group also performs system-level electro-photonic circuit design. A current project is investigating the use of a monolithically integrated InP platform to accomplish continuous-variable quantum key distribution (CV-QKD). The on-chip lasers, detectors, and modulators are controlled through an electrical interface designed in-house.
Photonic Crystals for Nonlinear Optics
A key ingredient for accomplishing highly-efficient nonlinear optical processes is strong optical intensities. Photonic crystals can help achieve high localized field intensities, thus resulting in efficient optical conversion processes. We are investigating photonic crystals in silicon and III-V semiconductors to achieve all-optical signal processing.
In addition to photonic crystal design, simulation, and characterization work, our group has extensive experience with advanced manufacturing techniques to realize high resolution photonic crystal devices.