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Drs. Jay Mathews and Imad Agha

University of Dayton Physics & Electro Optics Departments

September 18, 3:40 PM

Thirkield Hall (Physics), room 103


GeSn alloys for Si-based infrared optoelectronics

Silicon is the basis for a multi-billion dollar industry, but its optical properties have limited its use in optoelectronics for infrared (IR) applications. Many IR devices are currently made using III-V or II-VI materials, which has served to fill the gap. However, these materials tend to be expensive, and integrating the materials and devices into Si fabrication can be difficult. There are a number of applications that could benefit from Si integrated photonics including photovoltaics, infrared detection and imaging, optical interconnects (OICs), and photonic integrated circuits (PICs). In particular, OICs and PICs require efficient laser sources, modulators, low loss waveguides, optical switches, and photodetectors, all of which must be integrated into a single Si chip using complementary metal-oxide-semiconductor (CMOS) processing.

One possible solution to realizing some of these devices is to use GeSn alloys as the active material. These thin films are grown on Si substrates and compatible with standard Si processing techniques, they have band gaps in the infrared, and the band structure of GeSn yields more efficient optical absorption and emission than that in Si. These unique properties have prompted a recent effort to develop optoelectronics from GeSn films, and this research has resulted in a number of prototype photonic devices such as photodetectors that cover all telecommunications wavelengths, infrared light-emitting diodes, and optically-pumped waveguide lasers. Dr. Mathews will review some of this recent work and discuss the future impact of this exciting material for silicon photonics.

The University of Dayton (UD) has many opportunities for students to get involved in both undergraduate and graduate research. The Physics department at UD is an undergraduate only program, and our students are heavily involved with research throughout their undergraduate experience. While there is no physics graduate program at UD, we offer an MS and PhD degree in Electro-Optics through the Electro-Optics and Photonics (EOP) Graduate Engineering program, which is a unique multidisciplinary program that combines physics, optics, and electrical engineering to give students a highly specialized skill set for a future career in optics and photonics. The EOP program is geared toward practical application and involves a large amount of hands-on laboratory instruction, as well as unique courses in subjects such as nonlinear optics, electro-optical devices and systems, and optical radiation and matter. Dr. Agha will give an overview of the EOP program.

Dr. Jay Mathews is currently an Assistant Professor in the Department of Physics and the Electro-Optics Graduate Engineering Program at the University of Dayton. He obtained his BS with double major in Physics and Mathematics from Colorado State University in 2007, and he received his PhD in Physics from Arizona State University in 2011. Following graduation, Dr. Mathews was awarded a fellowship in the National Academy of Sciences Research Associateship Program, where he performed research for the US Army’s Benet Laboratories at Watervliet Arsenal in NY until July 2013. He joined the Physics department at UD in 2013. Dr. Mathews received an Air Force Office of Scientific Research Young Investigator Award in 2016.

After undergraduate studies in electrical engineering at the American University of Beirut, Dr. Agha moved to Cornell University for his graduate degree. After his PhD, he had a postdoctoral appointment at the Institut d'Optique in Palaiseau, south of Paris. He next joined the National Institute of Standards and Technology in Maryland as a member of the Nanofabrication Research Group. Currently Dr. Agha is an Assistant Professor in Physics and Electro-Optics at the University of Dayton.


Refreshments will be served at 3:30pm