Can you give us a little background about yourself?
I was born in Serbia where I also completed my initial education. I came to the US (Caltech) for graduate school, then moved up north (Stanford) for postdoc, and stayed here as a faculty. I am currently a professor of electrical engineering and by courtesy of applied physics at Stanford where I lead the nanoscale and quantum photonics research group. As you can conclude from my research group’s name, my areas of interest are nanophotonics and quantum photonics – primarily experimental. I am interested in fundamental studies of light–matter interactions and exploring the ways to harness them in order to build better photonic devices and circuits, for applications ranging from optical interconnects and communications, all the way to quantum technologies and biosensing.
How did you get into electrical engineering and when did you start?
Like most kids who end up in engineering, I loved building things and Legos were my favorite toy. I enjoyed math, physics, and programming, and went to a high school specialized in these subjects. Electrical engineering didn’t seem like an obvious career choice at first: I thought about architecture as an appealing combination of art and engineering, then I thought about studying physics or math and becoming a teacher, and finally settled on electrical engineering because it looked like a perfect combination of applied physics and math (and I cared about applications). My older brother was also studying electrical engineering, and that was a big influence.
Can you tell us about your work as a Professor at Stanford and a faculty member of the Ginzton Lab, Bio-X and the Pulse Institute at Stanford?
I lead the nanoscale and quantum photonics research group, with around 15 very talented graduate students and postdocs from around the world. Most of my daily activities are focused on research and interaction with my group members and collaborators. I also teach a number of classes, from freshman electromagnetics to graduate level class on optical microcavities and light-matter interaction.
How did you get your job? What jobs and experiences have led you to your present position?
I liked to both do research and teach when I was in grad school, and trying to get a job in academia seemed like a natural choice. However, the type of research that I do relies on sophisticated facilities for nanofabrication, and that somewhat restricted the choice of universities that I considered. I applied for faculty jobs when I was a postdoc and received offers from a few great schools. Since I was already at Stanford as a postdoc and familiar with high quality students and facilities critical for my research, I decided to stay here.
What award are you most proud of? Can you tell us about that award?
It is difficult to single out one award – I am proud of all of them in different ways. Of course, awards are not our motivation to do research, but they are a way of recognition of our work – research or teaching, and that type of feedback and acknowledgment is valuable.
Can you tell us about your research interests?
We are interested in fundamental studies of light-matter interaction, and to do this, we have to localize photons efficiently (for a long time and in a small volume), which in turn requires sophisticated optical structure designs. We used to rely on structures consisting of regular, geometrical patterns, but recent advances in optical design indicate that those may not be optimal solutions, and we (and others) have been developing some highly non-intuitive designs, by using machine learning techniques. In any case, resulting structures have small, sub-wavelength features and therefore, their implementation relies on the modern nanofabrication methods.
In my own research, these new structures have enabled many beautiful experiments, as well as applications. One of the most immediate applications is optical interconnects - replacing copper wires inside of computers with optical links. We already have building blocks for this (efficient, high speed devices), but they also need to have small footprints, to be robust to temperature variations and fabrication imperfections, and to be fully compatible with silicon electronics platform. We are working on addressing all of these issues, and putting all these building blocks together in an efficient way. Achieving this would dramatically decrease energy consumption in computers and data centers resulting from inefficient electrical interconnections, while increasing operating speed.
What are you currently working on?
I'll briefly describe a few relatively new projects in my group that we are excited about.
One is inverse design of nanophotonic devices, where we let a computer perform physics guided search of the full parameter space of fabricable photonic devices. So far, for every problem we addressed, we have ended up with better designs (in terms of efficiency, robustness, footprint) than conventional solutions. This work builds up on the PhD thesis of my former student Jesse Lu (now at Google). What started as a side project that only involved Jesse and myself, and our initial publication in 2013, in the meantime grew into a major project involving around half of my group.
Another area that we are very excited about is building attojoule optoelectronics (which is useful for optical interconnects) and quantum photonic devices using color centers in diamond and silicon carbide, for secure long distance quantum communications and computing.
Can you tell us about your publications?
In my area of research, the most important results are published in refereed journals. This is interestingly not the case for all areas of EE, and in some areas that are closer to computer hardware or software researchers publish primarily in conference proceedings. Of course, we also go to conferences to interact with other researchers and present our work, but we always publish main results in refereed journals.
Can you tell us about your professional activities?
Professional activities are an important part of our job and a way of giving back to the scientific community. Among my main professional activities, I am a member of the scientific advisory board of the Max Planck Institute for Quantum Optics in Munich, Germany, and of Ferdinand Braun Institute in Berlin, Germany. I also serve on the editorial advisory board of some journals – NPG Quantum Information and ACS Photonics and the moment, and am usually involved with refereeing papers and proposals, organizing conferences, workshops and other events in my field.
Is there anything you’d like to say to young people to encourage them to pursue electronics?
If you are interested in math, physics, and/or coding, you should consider electrical engineering. It is a very broad major, and this gives you a lot of flexibility: you can pursue many career options afterwards, including writing software, building circuits or other engineering systems, research, or teaching.
If you pick EE and are undecided about your future career choices (e.g. between industry and academia), apply for internships, work as a teaching assistant, mentor younger researchers - all of these experiences will help you learn more about various job options and hopefully help you decide.
Finally, in EE you also acquire so many skills that can help you get a job even outside of our field: I have former students working in venture capital firms, or as risk analysts.
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