Optoelectronic Device Group

Optoelectronic components continue to play a crucial role in evolving fiber optic systems as they are required to operate at higher and higher speed and at an increasingly higher spectral efficiency. High-speed applications in microwave photonics, including RF optical links, oscillators, and radar, call for integrated high-performance devices with higher bandwidth, better power handling capability, and higher linearity to improve signal-to-noise ratio and spur-free dynamic range. To meet future requirements of these applications photonic integrated circuits (PICs) combining optical, optoelectronic and eventually electronic functionalities on a single chip will become more and more important. Research in the Optoelectronic Device Group at UVa is focused on the development of photonic components and technologies that enable new applications and advances in a wide range of systems. Our work includes the development of state-of-the-art high-speed high-efficiency waveguide photodetectors, integrated optical coherent receivers, high-power photodiodes and arrays, and large dynamic range detectors.
 
Heterogeneous integration of III-V devices on silicon is a promising approach to realize high-performance optoelectronic devices on a silicon photonics platform. Owing to their material properties, Indium phosphide-based photodiodes (PDs) allow for complex bandgap engineering and have the potential to achieve low dark current, high saturation current and wideband absorption over C- and L-bands. We have demonstrated discrete InP-based modified uni-traveling carrier PDs that have achieved record-high saturation current and high linearity. In collaboration with UC Santa Barbara and Aurrion Inc. we have been using wafer-bonding technology to integrate this type of photodiode on Silicon-on-insulator waveguides. The goal of this work is to enable high-performance photonic integrated circuits on a versatile Silicon photonic-electronic platform.
 
The Optoelectronic Device Group uses a variety of design and simulation tools including Crosslight APSYS and ATLAS (semiconductor), Comsol (thermal), Beamprop and Fimmwave (optical), ADS (electrical), and automated layout tools (L-Edit).
Device fabrication is carried out in-house at the University of Virginia Microfabrication Laboratory: The facilities include 3500 square feet of clean room space equipped with all of the processing equipment necessary to fabricate state-of-the-art semiconductor devices.  Fabriation facilities include photolithography with back and front registration, SEM with focused ion beam, two e-beam evaporators, Oxford ICP-RIE, PECVD for SiO2 and SiN, wet chemical etching bays, E-beam lithography, rapid thermal anneal, and ellipsometry.  Additional facilities are available for the electrical, optical, and RF characterization of solid-state materials, devices and circuits. Our group uses a variety of equipment for optoelectronic device characterization including high-speed spectrum analyzer and network analyzer, sampling scopes, optical heterodyning, noise figure analyzer, high-power optical amplifiers, and fs pulse source. 
 

Academic collaborators:
Prof. Joe C. Campbell (ECE, UVa)
Prof. John Bowers (ECE, UCSB)
Prof. Archie Holmes (ECE, UVa)
Prof. Steven Bowers (ECE, UVa)
Prof. James Landers (Chemistry, UVa)
Prof. Olivier Pfister (Physics, UVa)

Collaborators in industry:
Finisar
Rockwell Collins
Freedom Photonics, LLC.
Aurrion Inc.
Phase Sensitive Innovations (PSI)
Georgia Tech Research Institute (GTRI)