Colloquium at The Institute of Optics

Colloquium: From Maxwell’s Equations and Quantum Mechanics to Engineered Optical Fiber for Mitigating Thermal Mode Instability

April 4, 2022


John Marciante

Co-founder of RAM Photonics

Professor, The Institute of Optics, University of Rochester


 Group Website


While fiber lasers appear to be ubiquitous, their application space is actually relatively limited due to physical impairments that only reveal themselves when performance is required outside of their current operational space.  One such example is relatively narrow-band amplification to very high power levels, where the spatially localized quantum defect (the energy difference between pump and signal photons) creates a dynamic long-period grating that couples light from the desired fundamental mode to other modes.  This thermally induced spatio-temporal instability destroys the output beam quality of the amplifier.  Understanding models initiated from Maxwell’s equations and applying principles from quantum mechanics to optical waveguides led to the development of new class of optical fibers – differential-mode-area (DMA) fibers – which, when properly engineered, can mitigate this thermal mode instability.  While years of fabrication trials have resulted in physically realized fibers that have nearly reached the intended design, the testing of such fibers requires a demanding experimental environment, including precision launch control, multi-kW pump lasers, mitigation of stimulated Brillouin scattering, a power-capable diagnostic suite, and engineered controls for safely conducting such testing.

BIO:  John R. Marciante received the B.S. degree in Engineering Physics from the University of Illinois at Urbana-Champaign in 1991 and the M.S. and Ph.D. degrees, both in Optics, from the University of Rochester, in 1992 and 1997, respectively. In 1991, he joined the USAF Phillips Laboratory in New Mexico (later to become the Air Force Research Laboratory) as a Research Physicist. In 2001, he returned to Rochester to join Corning Rochester Photonics Corporation as a Senior Research Scientist and the Institute of Optics as an Adjunct Professor. Since 2003, he has been with the University of Rochester.  He is currently an Associate Professor of Optics at the Institute of Optics. He has also held positions as Adjunct Professor at the University of New Mexico and Chairman for the IEEE/LEOS Albuquerque Chapter, and has served on numerous conference committees including OFC, SPIE Photonics West, and Frontiers in Optics.  He served two terms as Topical Editor for the Journal of the Optical Society of America B, and two terms as the Chair for the Fiber Modeling and Fabrication technical group of the Optical Society of America.  In 2009, he co-founded RAM Photonics, whose Rochester-based facility is focused on automated optical manufacturing, fiber optic interconnects, wavefront sensors, and directed energy laser weapons technologies.

TITLE: Dr. John Marciante TBA

DATE:  April 4, 2022

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