Meet David Barton III

David Barton III

Dr. David Barton III

Advisor: Marko Loncar

Institution: Harvard University

Bio: David Barton is a postdoctoral fellow in Marko Lončar’s group at Harvard’s School of Engineering and Applied Sciences. He received his bachelor’s degree summa cum laude in Chemical Engineering from the University of Minnesota in 2015. He then received his master’s degree (2018) and PhD (2020) in Materials Science and Engineering as a Stanford Graduate fellow at Stanford University, working with Prof. Jennifer Dionne. His PhD work developed a new platform for resonant, reconfigurable, and nonlinear phase gradient metasurfaces using guided mode resonances in nanoantennas. His work has been published in Nature Nanotechnology, Physical Review Letters, Nano Letters, and Applied Physics Letters. During his PhD, he was a finalist for SPIE’s “Active Photonics” series best paper competition in 2017 and was a 2019 Materials Research Society Graduate Student Award winner. As an Intelligence Community Postdoctoral fellow, David is investigating new integrated cavity designs for microwave-optical transduction and integrated photonics in thin-film Lithium Niobate. Outside of the lab, David is passionate about ceramic arts, French patisserie, and traveling.

Abstract: Entangled microwaves have emerged as a possible avenue for high sensitivity remote sensing of objects with low visibility, even when the detection channel has high noise or loss. However, current sources are not bright enough for use in deployable technology. My work has focused on new devices to overcome this challenge. One emerging technology with potential to create bright entangled microwaves is optical-to-microwave downconversion. Here, an optical photon is converted to a lower frequency while simultaneously generating a microwave photon. This technology can transduce quantum information from one domain to the other, potentially useful in distributed quantum computing and long-range quantum communication.

My current research focuses on two candidate architectures to achieve high efficiency optical-to-microwave transduction, both based on integrated cavity electro-optics. First, I have developed an integrated Fabry-Perot cavity in thin-film Lithium Niobate as a potentially new resonator geometry for integrated microwave-optical transduction. We have fabricated devices with optical quality factors exceeding 2.5 million, and are developing a coupled-cavity configuration that creates the microwave and optical resonances required for this transduction process. Second, we have improved our fabrication and designs of more traditional devices based on coupled ring resonators to generate higher transduction rates than previous demonstrations, working towards measuring non-classical correlations between optical and microwave photons. Finally, we are optimizing experimental conditions to measure transduction efficiency, noise generation, and the quantum nature of the downconverted photons. Together, these results will pave the way to efficient microwave-optical transduction, enabling long-haul quantum communication, remote sensing, and distributed photonic quantum computing.