Structured Light and Complex Media: Tailoring Light-Matter Interactions

ABSTRACT

Tailoring light–matter interactions require control over multiple degrees of freedom: the spatial structure of electromagnetic fields, the temporal dynamics of material properties, and the configuration of matter itself. In this talk, I will present how engineering these degrees of freedom enables unprecedented control over electromagnetic phenomena at multiple scales.

Structured illumination with cylindrical vector beams provides a powerful platform for manipulating light–matter interactions at the nanoscale. Through full vectorial analysis of focused generalized cylindrical vector beams interacting with spherical nanoparticles, I will show how the polarization structure of incident light can selectively excite and tune between electric and magnetic multipolar modes, opening pathways for polarization-controlled nano-optical spectroscopy.

Beyond spatial structuring, temporal modulation of material properties offers complementary control mechanisms. I will present the temporal analogue of Sommerfeld's classical half-plane problem, where rapid switching of plasma frequency presents intriguing phenomena—revealing fundamental insights into time-varying metamaterials and their potential for wave manipulation. Finally, I will discuss how swift electrons interacting with electromagnetic structures exhibit strong nonreciprocal responses, with space-time modulation of electron properties providing additional control over wave propagation.

These complementary approaches collectively illustrate how structured fields, temporal transitions, and engineered media converge to create new paradigms for controlling electromagnetic interactions across diverse physical systems.

BIOGRAPHY

Asma Fallah is a postdoctoral associate at the Institute of Optics at the University of Rochester, where she conducts research on structured and singular optics, as well as nanoscale wave–matter interactions, in the group of Prof. Eileen Otte. She earned her Ph.D. in Electrical and Systems Engineering from the University of Pennsylvania in 2025, under the supervision of Prof. Nader Engheta. Her doctoral dissertation was honored with the Joseph D'16 and Rosaline Wolf Award for Best Dissertation.

Her research spans metamaterials, metasurfaces, plasmonic optics, and time-varying electromagnetic structures. Prior to her Ph.D., she received her B.S. in Electrical Engineering from the University of Tehran in 2016. She is a recipient of the GWIS fellowship (2024-2025) and was selected as a Rising Star in EECS by MIT in 2024. Her work has been published in leading journals in optics and electromagnetics.