3D Hybrid Integrated Silicon Photonics

We have developed a novel integration platform that conveniently merges InP and GaAs devices with SiPh in a backend processing step. Light is coupled between layers using grating couplers and total internal reflection (TIR) turning mirrors. This integration platform enables laser integration for silicon photonics and multi-chip photonic interposers. An important feature is superior heat…

Laser Integration for Silicon Photonics with Heteroepitaxy

Commercially, laser integration for silicon photonics has been based primarily on hybrid integration. Future large-scale photonic integrated circuits based on silicon photonics will greatly benefit from monolithic integration of laser sources by direct heteroepitaxy on silicon. Our group has developed novel techniques to grow low-defect-density gallium arsenide (GaAs) and indium phosphide (InP) on exact oriented…

Integrated Microwave Photonics

Microwave photonics is the interplay between RF engineering and optoelectronics. In addition to high-performance active photonic devices (ex. lasers, photodetectors, modulators), we are developing novel integrated true time delay technologies based on ultra-low-loss waveguides for optical beam forming networks, and novel techniques to characterize group delay of resonator-based delays. Integrated microwave photonic technologies can enable…

Free Space Optical Communications

In addition to enhancing space exploration, space optical communications can deliver broadband connectivity to remote locations and can assist in disaster recovery. Integrated photonics is an ideal technology for deploying high-performance, space-qualified, and low cost, size, weight and power (CSWaP) photonic systems into space. Photonic integrated circuits (PICs) can be deployed on small spacecraft (ex.…

Emerging Materials and Integrated Nanophotonics

Novel materials such as indium tin oxide (ITO) and graphene demonstrate unique optoelectronic properties for compact devices such as optical modulators, switches, and phase shifters. We are working to integrate such materials in the silicon photonics platform to enable the next generation of integrated nanophotonic devices, and also utilize these technologies to build scalable arrays…

Transmitters and Receivers

In addition to the intensity, information can be encoded on the phase, frequency, and polarization of an electromagnetic wave to carry information. Advanced modulation formats utilize a combination of these properties to increase the data carrying capacity of transmission channels. Corresponding transmitters and receivers require many functions such as intensity modulators, phase modulators, phase shifters,…

On-Chip and Short-Reach Optical Interconnects

As the demand for data continues to increase, optical interconnects are becoming more attractive for on-chip and short-reach data links. Our group has been developing technologies for optical interconnects to and inside data centers, and we have also been investigating the design and architecture of optically interconnected manycore processor systems. Important technologies for these applications…

Template Assisted Selective Epitaxy

We are pursuing a unique selective area growth technique in 3D confined nano-structured templates called TASE (template assisted selective epitaxy) using our in-house metalorganic chemical vapor deposition (MOCVD) system. Fabrication of channel-like nanometer-scale horizontal structures allows for the selective deposition and lateral growth of group III-V semiconductor materials . Under a project led by Prof.…

Remote Sensing Lidar for Atmospheric Gas Detection

Monolithic integration of optical devices greatly reduces the cost, size, weight and power consumption (SWaP) of photonic systems. For space applications, this can enable deployment on smaller platforms and more frequent missions. This project aims to measure atmospheric constituents such as carbon dioxide (CO2) using a Lidar photonic integrated circuit s (PIC)s that are closely…