Headshot of Greg Steinbrecher
Headshot of Greg Steinbrecher


Greg Steinbrecher

Massachusetts Institute of Technology


Greg is a Ph.D. candidate in the Quantum Photonics Group at the Massachusetts Institute of Technology, advised by Professor Dirk Englund. Greg received his S.B. in physics and electrical engineering from MIT in 2012 and his MEng. in electrical engineering and computer science in 2013. His research interests lie at the intersection of quantum physics, communications, and systems engineering.

Research Summary

As Moore’s law – combined with the ever-increasing connectivity of our society – has driven an exponential incrase in the data carried by our networks, there has been a trend of replacing electrical links over copper wires with photonic links over optical fibers. At first these systems were large, replacing only the long-haul links that comprise the backbone of the internet. However, in recent years, optical communications systems have made its way into both the datacenter and the home. This has driven the miniaturization of optical technologies, most recently into silicon photonics systems.

Silicon photonics leverages the advances in nano-scale fabrication of silicon circuits to create tiny circuits to direct, modulate, and otherwise control photonic signals. This fabrication, at industrial quality, has recently become available to academic customers, enabling investigation of optical systems that were previously too physically large to be viably built in the laboratory, either due to space constraints or the inability to stabilize such large systems down to the required length scales of less than 100 nanometers.

Greg’s early Ph.D. research has focused on using silicon photonics to develop a quantum photonic processor – a silicon photonics system that can be programmed to perform arbitrary linear operations on quantum states of light. This work has required the development of custom electronics systems, new characterization techniques to mitigate variations in the fabrication of these circuits, application of somewhat obscure graph theory, automated characterization and control software, and more; the joy of the project has been how many different layers of thinking are required to work together.

Currently, Greg is looking at applying these integrated photonics systems to problems in optical networking. In particular, he is currently developing a demonstration of a novel type of network switch that has the potential to reduce both latency and power usage in optical networks, particularly in data centers. He also continues his work on applying these systems to quantum photonics.