Fall 2022/Spring 2023

Seminar Coordinators:

Generalized Space-Time Engineered Modulation (GSTEM) Metamaterials

  • Christophe Caloz, Ph.D.
  • Postponed
  • This is a virtual meeting. Please email: Pamela_Morel@uml.edu for the Zoom link 72 hours prior to the seminar.


In this talk, Christophe Caloz, Ph.D. will present a global and extended perspective of electrodynamic metamaterials formed by space and time engineered modulations, which we name Generalized Space-Time Engineered Modulation (GSTEM) metamaterials, or GSTEMs. This perspective describes metamaterials from a unified spacetime viewpoint and introduces accelerated metamaterials as an extra type of dynamic metamaterials. First, it positions GSTEMs in the even broader context of electrodynamic systems that include (nonmodulated) moving sources in vacuum and moving bodies, explains the difference between the moving-matter nature of the latter and the moving-perturbation nature of GSTEMs, and enumerates the different types of GSTEMs considered, namely space EMs (SEMs), time EMs (TEMs), uniform space-time EMs (USTEMs), and accelerated space-time EMs (ASTEMs). Next, it establishes the physics of the related interfaces, which includes direct-spacetime scattering and inverse-space-time transition transformations.  Then, it exposes the physics of the GSTEMs formed by stacking these interfaces and homogenizing the resulting crystals; this includes an original explanation of light deflection by USTEMs as being a spacetime weighted averaging phenomenon and the demonstration of ASTEM light curving and black hole light attraction. Finally, it discusses some future prospects.


Christophe Caloz received the Diplôme d'Ingénieur en Électricité and the Ph.D. degree from École Polytechnique Fédérale de Lausanne (EPFL), Switzerland, in 1995 and 2000, respectively. From 2001 to 2004, he was Postdoctoral Research Fellow at the Microwave Electronics Laboratory, University of California at Los Angeles (UCLA). In 2004, he joined Polytechnique Montréal, where he was a Professor (Assistant 2004, Associate 2006, Full 2010) and the holder of a Canada Research Chair (Tier-II 2005-2015 and Tier-I 2015-2019) in Metamaterials until 2020. In 2020, he joined KU Leuven as a BOFZAP Research Professor and as the head of the META Research Group.

Professor Caloz has authored and co-authored over 800 technical conference, letter and journal papers, 17 books and book chapters, and he holds a dozen patents. His works have generated over 35,000 citations, and he is a Thomson Reuters Highly Cited Researcher. He received a number of awards, including the UCLA Chancellor's Award for Post-doctoral Research in 2004, the MTT-S Outstanding Young Engineer Award in 2007, the E.W.R. Steacie Memorial Fellowship in 2013, the Prix Urgel-Archambault in 2013, the Killam Fellowship in 2016, and many best paper awards with his students at international conferences. He has been Fellow of the Institute of Electrical and Electronics Engineers (IEEE) since 2010, a Distinguished Lecturer of the Antennas and Propagation Society (AP-S) from 2014 to 2016, Fellow of the Canadian Academy of Engineering (CAE) since 2016, and a Fellow of Optical (formerly Optical Society of America - OSA) since 2019.

He was an Associate Editor of the Transactions on Antennas and Propagation of AP-S from 2015 to 2017 and elected as a member of the Administrative Committee of AP-S from 2014 to 2016. From May 2014 to November 2015, he was a Distinguished Adjunct Professor at King Abdulaziz University (KAU), Saudia Arabia. He previously was a Member of the Microwave Theory and Techniques Society (MTT-S) Technical Committees MTT-15 (Microwave Field Theory) and MTT-25 (RF Nanotechnology), a Speaker of the MTT-15 Speaker Bureau, the Chair of the Commission D (Electronics and Photonics) of the Canadian Union de Radio Science Internationale (URSI), an MTT-S representative at the IEEE Nanotechnology Council (NTC), and the instigator of the URSI XXIInd General Assembly and Scientific Symposium (GASS) (Montréal, 2017). In 2009, he co-founded the company ScisWave (now Tempo Networks). He has been a scientific advisor of several RF and optical companies. His research interests include all fields of theoretical, computational and technological electromagnetics, with strong emphasis on emergent and multidisciplinary topics, such as metamaterials and metasurfaces, quantum and nano electromagnetics, space-time electrodynamics, photophononics, exotic antenna systems and real-time radio/photonic processing.

Frequency Transformation from Microwave to Terahertz by a Time-varying Medium

  • Dikshitulu K. Kalluri, Professor Emeritus University of Massachusetts Lowell
  • April 20, 2023 at 2 p.m. EST
  • This is a virtual meeting. Please email: Pamela_Morel@uml.edu for the Zoom link 72 hours prior to the seminar.


At a temporal discontinuity in the electromagnetic property of a medium, the wave number k of an electromagnetic wave is conserved while the frequency f changes as needed by the requirements of the changed medium. This simple principle can be used to generate a number of applications. One of them will be discussed in the talk.

Frequency and Polarization Transformation: 10 GHz to 1000 GHz. If such a device is inexpensive (say less than $100) it can be a commercial success. Such a transformer can be used to transform off-the-shelf microwave source to provide, not easily obtained, terahertz source. A conceptual design, based on a FDTD simulation of such a device involving a fast decaying magnetized plasma in a millimeter size cavity will be discussed (D. K. Kalluri and R. K. Lade, IEEE Transactions on Plasma Science Nov. 2012). Interesting Physics, involving "interband photonic transition" will be also discussed.


Dikshitulu K. Kalluri, Ph.D, is a Professor Emeritus of Electrical and Computer Engineering at the University of Massachusetts Lowell. He received his B.E. degree in electrical engineering from Andhra University, India; a D.I.I. Sc. degree in high-voltage engineering from the Indian Institute of Science in Bangalore; earned a master's degree in electrical engineering from the University of Wisconsin, Madison, and his doctorate in electrical engineering from the University of Kansas, Lawrence.

Professor Emeritus Kalluri began his career at the Birla Institute of Technology, Ranchi, India, advancing to the rank of Processor, heading the Electrical Engineering Department, then serving as (Dean) Assistant Director of the institute.

Since 1984, he had been with the University of Massachusetts Lowell, Lowell, advancing to the rank of full processor in 1987. He coordinated the doctoral program (1986-2010) and co-directed/directed the Center for Electromagnetic materials and Optical Systems (1993-2002/2003-2007). As part of the center he established the Electromagnetics and Complex Media Research Laboratory. He had collaborated with research groups at the Lawrence Berkeley Laboratory, the University of California Los Angeles, the University of Southern California, New York Polytechnic University, the University of Tennessee, the Montreal Polytechnic, and has worked several summers as a faculty research associate at Air Force Laboratories. His recent collaboration is the Professor Christophe Caloz on Space-Time Modulated Media. He retired in May 2010 but continues his association with the university through the graduate programs. He continues to teach his graduate courses on-line as Professor Emeritus.

CRC Press published his two recent books: in April 2010 'Electromagnetics of Time Varying Complex Media Second Edition' and the first edition of the book Electromagnetic Waves, Materials, and Computation with MATLAB in August 2011. The second edition is published in October 2017 in 2 volumes, Principles of Electromagnetic Waves and Materials, and Advanced Electromagnetic Computation. He has published extensively on the topic of Electromagnetics and Plasmas. He supervised doctoral thesis research of 17 students.

Professor Emeritus Kalluri is a fellow of the Institute of Electronic and Telecommunication Engineers and a Senior Member of IEEE.

THz Technology: The Move from Scientific to Commercial Applications - 6G, Space & More

  • Jeffrey Hesler, Ph.D.
  • December 7, 2022 at 1 p.m. EST


The Terahertz field has long been used for a wide variety of scientific applications, ranging from radio astronomy, spectroscopy, fusion plasma diagnostics, and more. The potential of non-scientific applications of THz has been understood for many years, but technological limits slowed the advance of these applications. The past decade has seen dramatic advances in transistor technology that is now enabling rapid progress in a variety of applications, ranging from basic test and measurement, ultra-wideband communications, and the use of THz radiometers in space for next generation commercial weather forecasting. This talk will describe two scientific THz examples, the THz local oscillators for the Atacama Large Millimeter-wave Array (ALMA) and an 874 GHz radiometer that was flown on NASA-GSFC's IceCUBE cube satellite. The talk will then present examples where the same base technology is used in THz test and measurement, including broadband signal generation and detection to 5G/6G and THz vector network analysis.


Jeffrey L. Hesler (F'22, M'86, SM'19) is the Chief Technology Officer of Virginia Diodes and an IEEE Fellow. For more than 30 years he has been working on creating new technologies that utilize the Terahertz (THz) frequency band for scientific, defense, and industrial applications. He has published over 200 technical papers in journals and international conferences proceedings, is the Chair of IEEE Technical Committee MTT-21 (THz Technology and Applications) and is a co-Editor of the IEEE Transactions on Terahertz Science and Technology. Terahertz systems based on his innovative designs are now used in hundreds of research laboratories throughout the world.