I remember being beyond stressed about finding a summer internship. There were so many opportunities being presented by the advising department in different realms of physics, everything from biophysics to astrophysics and everything in between. It was overwhelming how many things there were to apply to, I didn’t know where to start. Everyone around me seemed so sure of what they were doing and what field they were interested in. It felt like they had their entire career figured out by day 2 of sophomore year, and I was falling behind.

Thankfully, I was accepted to the AIM Photonics Future Leaders Program, which is a program that acquaints undergraduates with the field of photonics. On the first day, I found out I was assigned to work on optimizing quantum dot lasers epitaxially grown on silicon substrate. The first time I read that project description I had a miniature heart attack: I knew what maybe two of those words meant (“dot” and “laser”). I was struck with how little I knew about what I was about to walk into and how entirely unqualified I was to be working here. I was terrified I was going to embarrass myself in front of graduate students and researchers, or even worse, ruin the experiments.

After three full weeks of running measurements, attending lab group meetings and seminars, and digesting a hefty chunk of a textbook about lasers, I can comfortably say I know what my work is about. I’ve only dropped the tiny little lasers I have to transfer from their case to the microscope stage twice, I have yet to break anything extremely expensive (knock on wood). And yet, I’m still far from comfortable in my setting. My severe case of impostor syndrome has quieted from a piercing scream to dull background noise, but I still feel my stomach tighten when my graduate mentor watches me take a measurement. People that I share lab space have seen me around enough to think I belong and will sometimes ask me questions, and I nine times out of 10 have zero clue how to answer them.

This feeling of discomfort is important to me, though. It’s how I know I’m growing as a student and a researcher. Research is what I want to do as a career, it’s what I hope to do indefinitely. If I didn’t still feel these growing pains it would mean I’m not pushing myself hard enough. Comfortable is boring, and that’s why I love physics and photonics: it’s not there to coddle you, it’s there to push you.

What am I working on and why is it important?

The arrival of the internet has fundamentally changed so many aspects of our lives whether it be through business, communication, education, or entertainment, just to list a few. And in order to support such a huge amount of internet traffic, we rely heavily on data centers. Data centers are facilities that contain many computers and other necessary hardware. These computers talk to each other and are responsible for data storage, analysis, and processing.

Unfortunately, data centers are power hungry and energy inefficient. However, the integration of optical circuit switches in data center interconnects has shown great promise in terms of improving energy efficiency. Optical circuit switches are made up of multiple copies of a subcomponent that directs how light travels. A subcomponent is made up of an optical ring and it’s corresponding heater. Optical rings are wavelength selective filters that shifts depending on the temperature generated by the heater, thereby acting as a reconfigurable switch. My job this summer is to simulate these optical ring and heater systems in order to determine which configuration yields the widest thermal tuning range at the lowest power.

What’s my impression of research?

Some days can feel frustrating. Sometimes I spend a day or two trying to figure out how to fix the newest problem I’ve run into and it turns out to just be another silly mistake. At times, it’s easy to lose sight of the big picture and get really bummed out, but when something finally works it feels amazing! Food will taste that much better and my body will suddenly feel so much lighter.

It’s also really cool to see how all the things I’ve learned in the past three years have given me more confidence to approach new material. During junior year, I took a fabrication class that included clean room experience. I learned a lot about what goes on into actually making a chip from a bare silicon wafer. When I started doing research and reading papers, it was really cool when I was able to understand certain fabrication terms and procedures. It made the new material much less intimidating. I think my classes have definitely helped me get comfortable with that uneasy feeling of not knowing what in the world is going on and still having to plow through.

What are some cool perks of the AIM program?

I really love the career development seminars (every Monday) because professionals from different institutions are invited to present on their research and their careers. Also, we have workshops every Friday where professors teach how to successfully deliver an elevator pitch or nail a Powerpoint presentation. And even though I dread presenting in front of actual people, I really appreciate the emphasis they put on public speaking.

How do you simulate a laser? That was my first question, followed by many more, for my mentor starting at the beginning on the summer. Transitioning from a week of final exams to working in a new lab the next week is just about as hectic as it sounds, but also exciting.

As for simulating a laser, from my experience so far, it is done by reading multiple books on the subject and hoping that my lack of programming experience doesn’t hinder me too much. My project is based on narrowing the linewidth of an silicon-based laser, which is essentially making its frequency more precise. Since lasing is a process that takes place with a seemingly uncountable number of atoms, the frequency of the photon released from each atom is very slightly off from that from a different atom. Because of this, when we talk about the frequency of a laser, we are talking about the peak in a distribution of frequencies, not the frequency of every photon emitted by a laser. A smaller linewidth means that the distribution gets narrower, and more photons have a frequency closer to that of the peak.

Now that seems pretty interesting, but where are the applications? Well, there are plenty actually. By making a laser more precise, you can distinguish two lasers with closer frequencies. Since there will be less overlap which will contribute to detection errors and noise, devices will be able to pack more frequencies into the medium they use to transfer information. This is very important for communication, and I will give a quick example of why using a frequency we don’t work with in our research but is still representative of the importance of a narrow linewidth. KCSB FM, the radio station at UCSB, is broadcasted at 91.9 MHz. Like any other radio station, its frequency goes to only one decimal place. However, with a narrower linewidth on broadcasting and receiving instruments, channels will be able to further than that, having two or three decimal places with minimal overlap. This will open up many more channels, allowing more information to be accessible to anyone at a given time. A similar process can be used in optical fibers, except within a different range of frequencies.

Learning how to code has been a challenge for me so far, but has been a majority of what I have been doing. In fact, I have not set foot inside of a laboratory this summer, but have spent many hours at a desk. Reading and problem-solving is something that isn’t foreign to me after a few years of studying physics at UCSB, however it is new to me for research. I was expecting hands-on projects, with the lab coat and all, but what I have been doing is rewarding in a way I have never considered. And in the coming weeks, I think the time I spent reading and learning how to code will help me contribute to the solution of the growing problem of data transfer. Even though I don’t get to work with any fancy machines I had to get trained specifically for, working outside the lab has let me see the bigger picture and contribute in ways I never thought I could.