ECE Colloquium with Vassilios Kovanis

Starts:
4:00 pm on Tuesday, October 1, 2013
Location:
Photonics Center, 8 Saint Mary’s St., Room 339
URL:
http://www.bu.edu/ece/files/2013/08/Kovanis_10-01-13.pdf
Sharp Tunable Photonic Oscillators

With Vassilios Kovanis
Air Force Research Laboratory

Refreshments will be served outside Room 339 at 3:45 p.m.

Faculty Host: Jonathan Klamkin

Abstract: Limit cycle oscillators are used to model a broad range of periodic nonlinear phenomena. Using the optically injected semiconductor oscillator as key architecture paradigm, we will demonstrate that at specific islands in the optical detuning and injection level map, the period one limit frequency is simultaneously insensitive to multiple perturbation sources. In our system these include the temperature fluctuations experienced by the master and slave lasers as well as fluctuations in the bias current applied to the slave laser. Tuning of the oscillation frequency then depends only on the injected optical field amplitude. Experimental measurements are in good quantitative agreement with numerical modeling and analysis based on reduced generalized Adler type equations. These special operating regions should prove valuable for developing ultra-stable nonlinear oscillators, such as sharp linewidth, frequency tunable photonic microwave oscillators. Finally, the concept of an Isochron originally developed in mathematical biology will be reviewed and placed on context for efficient design of stable frequency sources via systems of coupled limit cycles oscillators.

About the Speaker: Vassilios Kovanis is a member of the technical staff at Sensors Directorate of the Air Force Research Laboratory. His responsibilities include managing an Air Force Office of Scientific Research for optical diverse waveform generation and low noise oscillators. He serves as a DARPA agent for the Microsystems Technology and Strategic Technology Offices in the areas of microwave photonics and transformational antenna programs. He was the lead program manager on the Optical Metamaterials SENSORS Directorate enterprise. He studied physics at the University of Athens, Greece, followed by graduate work at Temple University in Philadelphia, Pennsylvania, and wrote his Ph.D. dissertation at the University of New Mexico, in Albuquerque, New Mexico, in condensed matter theory. In September 1989, he joined the Nonlinear Optics Center at the Air Force Weapons Laboratory at the Kirtland Air Force Base. He remained with that organization for the next eleven years, working on multiple projects of optical and electronic technologies. During that period he held research faculty positions with the Applied Mathematics and the Electrical Engineering Departments at the University of New Mexico and was a National Research Council Fellow between 1992 and 1994. Subsequently he did a stint in corporate research and development laboratories with Corning Incorporated in Corning as a Senior Research Scientist and with BinOptics Corporation in Ithaca, New York, as a program manager for next generation photonics product development. Between 2003 and 2005, he was a member of the faculty at the Applied Mathematics Department at the Rochester Institute of Technology. His research interests are in designing low-noise tunable photonic oscillators, photonics synthetic matter and applications of compressive sensing to photonic receivers.