Myoung-Gyun Suh: Harnessing Light for an Information Society

Dr. Myoung-Gyun Suh is a Senior Scientist in the Physics & Informatics (PHI) Lab, which he joined in July 2019. He is also a Visiting Scientist at the California Institute of Technology (Caltech), where he received his Ph.D. in Applied Physics in 2017. He has also served on the research staff at the Samsung Advanced Institute of Technology. In recent years, Dr. Suh’s research has been related to the development of on-chip optical sources and their application to precision measurements. His work has focused on understanding nonlinear or quantum optics in high-quality-factor microresonators and utilizing them to develop narrow-linewidth lasers, chip-scale optical frequency combs, and optical sensors. At the PHI Lab, his work aims at developing novel optical tools and hardware architectures for information processing. Please read on to learn more about Dr. Suh’s background and areas of research.

How did you first get into optics research, and why Caltech for graduate school?

When I was an undergrad at KAIST (Korea Advanced Institute of Science and Technology) in the early 2000s, I did research in Prof. Yong-Hee Lee’s group where I learned about photonic crystals. Photonic crystals looked interesting because they can manipulate the propagation of light on a very small scale, and people thought of using them for optical computing. I was fascinated by the interesting physics of photonic crystals and the vision for optical computing. This is how I first got into optics research. Then I spent a few years at the Samsung Advanced Institute of Technology before joining the Ph.D. program at Caltech, which had several strong optics research groups in my areas of interest. The living environment there was also great for my family.

In your dissertation, you focused on optical micro-resonators; in particular, on soliton mode-locking microcombs and a novel spiral resonator, along with various applications. Why that topic? Was it the precision of these optical systems that intrigued you?

Before Caltech, my research topics were photonic crystals, GaN (gallium nitride) light-emitting diodes, and photovoltaics. I was not specifically interested in microresonators back then. However, my Ph.D. advisor, Prof. Kerry Vahala, introduced me to optical frequency combs and told me the group was interested in generating optical frequency combs using optical microresonators. I also had a chance to learn the subject from Dr. Scott Diddams, who is a pioneer of optical frequency combs, when he was visiting Caltech as a Moore Scholar. The research topic looked very interesting and important, because the level of precision that optical frequency combs can offer is unprecedented and what only optics can achieve. Miniaturizing such an important optical source using optical microresonators for various real-life applications was very exciting to me. That’s how and why I got into optical microresonator research, especially for optical precision measurement applications.

And you’re still working in these areas? How has your research evolved since then?

Yes, I am still working in the research area of optical microresonators and microcombs. More recently, I’ve begun to focus on microcomb applications to optical communication and computation.

What led you to join the PHI Lab? Does your optics research overlap with the PHI Lab’s other research areas?

As stated in our website, the PHI Lab’s interest or mission is to build simple, efficient, and practical solvers for real-world problems by rethinking “computation” within the fundamental principles of quantum physics and brain science. Moreover, the PHI Lab wants to use optical platforms for such research. This research theme of the PHI Lab was very attractive to me. I have been working on optics research for my entire career, and I enjoy asking and answering philosophical questions about physics and human intelligence. The PHI Lab seemed to be a perfect place to pursue my intellectual curiosity. Professor Yamamoto and many of the current PHI lab members have been studying the Coherent Ising Machine (CIM), which is a special type of optical computing system to solve combinatorial optimization problems. Microcombs can provide massive optical parallelism and high-clock frequency for such an optical computing system. In addition, microcombs can offer energy efficiency and compactness.

Does the new optics laboratory in Sunnyvale impact your work in any way?

As an experimentalist, I must say that the optics laboratory in Sunnyvale is very important for my work. I spent almost two years building experimental setups, and the lab now has many advanced capabilities for the kind of state-of-the-art optics research that I mentioned earlier. The new optics lab is essential part of my research, and I am extremely grateful to NTT Research for the support.

What would you say has been the most notable research of your career so far, from a personal or professional perspective? 

I guess the most notable research of my career is related to microcombs and their applications in precision measurements, such as spectroscopy and optical atomic clock. I was very lucky to be part of several initial microcomb research projects with former colleagues at Caltech and many collaborators.

Is there any forthcoming research that you’d like to mention?

There are a few research projects that I am currently working on, from device-level microcomb research to system-level optical computing research. It’s a bit early to talk about the details of these ongoing projects, but the main idea is all about how to utilize massive optical parallelism and high-clock frequency of microcombs for information processing.

Learn more about Myoung-Gyun Suh in his profile video here: Myoung-Gyun Suh, Research Scientist, PHI Lab (