Speaker: Dr. Tingyi Gu, U of Delaware
Title: "Engineering Material Transformations for Integrated Photonics: From Phase Change to Space Radiation"
Abstract: The functionality and reliability of integrated photonic devices are fundamentally linked to how materials respond to optical, electrical, thermal, and environmental stimuli. In this talk, I will discuss our efforts to understand and engineer such material transformations for integrated photonics, spanning chalcogenide and two-dimensional materials, nonvolatile photonic tuning, and space radiation effects in silicon photonic circuits.
I will first discuss the integration and processing of chalcogenide materials and their structural transformations at the micro- and nanoscale. Building on this foundation, we investigated layered In₂Se₃, where structural phase transitions provide a route toward nonvolatile integrated photonic memory. In few-layer tellurium-based materials, we further explored light-induced chemical transformation as an alternative mechanism for post-fabrication modification of photonic resonances. These studies illustrate how structural, chemical, and optical properties of emerging materials can be coupled to photonic devices to achieve functionality that is difficult to realize using conventional silicon alone. Finally, I will turn to a different type of material transformation: the interaction of integrated photonic devices with energetic particles traveling near the speed of light in space. Through space exposure and subsequent characterization of silicon photonic modulators and resonators, we investigate how radiation-induced changes at the material and device levels translate into photonic circuit performance and reliability.
Bio: Tingyi Gu is an Associate Professor of Electrical and Computer Engineering at the University of Delaware, where she leads the Lightwave NanoComponent Group. She received her B.S. in Electrical Engineering from Shanghai Jiao Tong University and her Ph.D. in Electrical Engineering from Columbia University. Her research focuses on integrated photonics and nanophotonics, with particular interests in silicon photonics, integrated metasurfaces, non-Hermitian photonics, crystalline material integration for large-scale circuit functions. Her group has pioneered integrated photonic metasurfaces for on-chip wavefront shaping and machine learning and performed the first space tests of photonic integrated circuits. She is a recipient of the Presidential Early Career Award for Scientists and Engineers (PECASE), NSF CAREER Award, DARPA Young Faculty Award, ARO Young Investigator Award, AFOSR Young Investigator Award, and NASA Early Career Faculty Award. She is a Fellow of Optica and a Senior Member of IEEE.
In person attendance at this seminar is only open to Columbia University affiliates. External guests are welcome to attend remotely. Please contact [email protected] if you need the Zoom link for this seminar.
