#large-scale-integration #energy-consumption

Technical talk by Professor Rajveer Nehra from the University of Massachusetts Amherst at the invitation of UVA IPS.

 

Abstract: Very-large-scale integration (VLSI) transformed computing by combining billions of transistors with scalable manufacturing and powerful design tools. As energy consumption, data movement, and interconnect bandwidth increasingly constrain processor performance, integrated photonics offers a complementary approach: computing and communicating with light in compact, programmable circuits. Optical interference and parallelism across wavelength enable high-throughput classical processing and communication, while engineered quantum states and measurements offer routes to exponential computational advantages for certain tasks. Realizing these opportunities requires a transition familiar from microelectronics: from individual devices to scalable, controllable, and manufacturable systems.

In this colloquium, I will present our work toward large-scale classical and quantum photonic processors using thin-film lithium niobate, which combines low-loss, ultrafast switches, and strong nonlinear interactions. I will show how confining light to nanoscale waveguides enables ultrafast all-optical switching, parametric amplification, and the generation and measurement of quantum states. Drawing parallels with VLSI, I will discuss the advances in materials, fabrication, circuit design, and electronic–photonic integration needed to translate these capabilities into next-generation processors.

 

Bio: Rajveer (Raj) Nehra is an Assistant Professor of Electrical and Computer Engineering at the University of Massachusetts Amherst, with affiliations in Physics and the Manning College of Information and Computer Sciences. Prior to joining UMass, he was a postdoctoral scholar at Caltech and a visiting professor at the University of Tokyo. He received his Ph.D. in Physics from the University of Virginia, where his research earned the Outstanding Graduate Research Award and the Allan Talbott Gwathmey Memorial Award. His research focuses on integrated photonics for next-generation information systems. His research program is supported by DARPA INSPIRED and the NSF VINES program.