Event
MSE Seminar: Dr. David Barton, Northwestern
Wednesday, April 29, 2026
3:30 p.m.
Room 2110 Chemical and Nuclear Engineering Building
Sherri Tatum
301-405-5240
statum12@umd.edu
"Active and dynamic photonic devices in electro-optic thin films"
Abstract: The abundance and complexity of information in light and images makes it a natural medium for transmitting and processing information. Indeed, it’s been hypothesized that processing these complex visual cues was the evolutionary pressure that led to the modern brain’s acuity. Modern computing, in fact, utilizes algorithms inspired by the brain’s incredibly efficient way of processing this information. Exploring new ways to use light to transmit, receive, and compute information can therefore unlock new devices for optical computing, communications, and sensing. A core requirement for this is finding fast and efficient ways of controlling a material’s optical properties.
This presentation will discuss several ways we are exploring light-matter interactions, materials development, and nanofabrication to advance Lightwave technologies. I will focus on electro-optic materials, which lack inversion symmetry and whose optical properties can be modified by an electric field. I will show a variety of devices in thin film lithium niobate on insulator where the direct connection between electric fields and optical properties have enabled miniaturized and advanced performance. Next, I will discuss devices based on nanophotonic barium titanate on insulator (BTOI). We developed a nanofabrication process to create low loss (Q > 500,000) waveguides with a high electro-optic coefficient (>150 pm/V) and demonstrate nanophotonic modulators based on photonic crystals with bandwidths exceeding 10 GHz. The improved electro-optic properties compared to lithium niobate, combined with its CMOS compatibility, make this material system particularly interesting. We use polarization-resolves confocal second harmonic generation microscopy to visualize domain inversion of these films in a quasi in operando manner. We explore the poling and depoling dynamics of this material, which has important implications in programmable nonvolatile optical devices and systems, as well as nonlinear optics based on quasi-phase matching. Finally, I will discuss future opportunities in these technology spaces that could be enabled with improved light-matter interactions in low-loss dielectric and semiconductor devices. These results point to a materials-centric view of photonic devices to enable new applications in communications, computing, and sensing.
Bio: Prof. David Barton is an assistant professor of materials science and engineering at Northwestern University. He started his independent career in 2024 following his PhD in materials science from Stanford, working with Jennifer Dionne, and postdoctoral training at Harvard, working with Marko Loncar. His research focuses on developing materials and devices in integrated photonics and metasurfaces, with a particular emphasis on reconfigurable and dynamic nanophotonics. He is the recipient of the Materials Research Society graduate student award, an intelligence community postdoctoral fellowship, and a Searle Fellow for teaching and Learning at Northwestern.
