Colloquium at The Institute of Optics

Extreme Dynamics in Semiconductor Lasers Under Modulation

April 18, 2022


Nicholas G. Usechak, Director of Ultrafast Photonic Devices and Research Laboratory

U.S. Air Force Research Laboratory

Group Website


ABSTRACT:  This talk will provide a few comments for future job seekers, a brief overview of the Air Force Research Laboratory, and an introduction to injection-locked semiconductor lasers.  Following this, we will jump into the recent experimental observation of extreme dynamics in semiconductor lasers under strong current modulation.  These results will then be explored through numerical simulations that are found to exhibit the same dynamics as those discovered experimentally. 

In this work, the benefit of the numerical simulations is that they can be used to provide insight that is not limited by experimental test equipment.  Moreover, enable us to explore more than the time-dependent output power of the laser which is all one has easy access to experimentally.  We are still in the midst of interpreting the results provided by the model in an effort to understand the underlying mechanism associated with this behavior.     


He worked at Trumpf Photonics in Cranbury, NJ as a Senior Engineer for a year following graduation characterizing high-power semiconductor laser arrays, automating experiments, and modeling the thermal effects of solder interfaces using transient temperature-extraction experiments to ground those models.  After Trumpf he joined the Air Force Research Laboratory at Wright–Patterson Air Force Base where he is currently employed as a Principal Electronics Engineer. In addition to his research activities at AFRL, where he runs the Integrated Photonic Circuits team and the Ultrafast Photonics Devices and Research Laboratory, Dr. Usechak also serves as the Program Manager for AIM Photonics and supports DARPA on a number of programs.

At Lehigh he was a Presidential Scholar during the academic year 1999-2000.  At the University of Rochester he conducted his experimental work in the Laboratory for Laser Energetics where he was a Frank J. Horton Fellow.  His research interests include integrated photonic devices and systems, nonlinear optics, fiber lasers, semiconductor lasers, ultrafast optics, high-speed test and measurement, high-power semiconductor lasers, mode-locked lasers, parametric processes, optical clock generation, novel gain media, diverse waveform generation, partial differential equations, delay differential equations, and numerical modeling.

Dr. Usechak is a member of the OSA, Tau Beta Pi, Sigma Xi, and a Senior Member of the IEEE.



DATE:  April 18, 2022

TIME: 3:30 PM - 4:30 PM (EDT)