The Integrated Quantum Optics (IQO) Group of Prof. Dr. Christine Silberhorn welcoming Jérémy Kelly-Massicotte from Canada from the PERIMETER INSTITUTE FOR THEORETICAL PHYSICS in Waterloo. Jérémy will gain an impression at the IQO Group correctly how waveguides physically work in practice.
In an interview we learn more about Jérémys stay here at the IQO Group at Paderborn University:
How did you come up with the idea to come to Paderborn for such a long time (3 months)?
The idea came from my supervisor Agata Branczyk, who has close ties with Christine and a few other members of her IQO group. It was one of the first things we've discussed when I started working with her for my master's degree. It played out well for me, because I've previously considered a student exchange to Germany and had spent a good amount of time trying to learn the language and some of its culture.
Do you work here on the "same project" as in Canada?
Matteo Santandrea (Member of IQO Group), me and my supervisor were already in the process of a collaboration before I came here. Most of my time spent here was directed toward that collaboration and learning about other people's work, but I've also been wrapping up previous work that is featured in a paper (<link https: arxiv.org abs>arxiv.org/abs/1807.01015) that will be published soon.
Which working group in Canada are you from?
I do my research work at the Perimeter Institute under Agata Branczyk supervision. To give you an idea, I was the first graduate student to join the group, roughly one year ago. I've been followed since by Eugene Adjei, doing his PhD and Nicolàs Quesada as post doc.
In which research work are you involved with in Paderborn?
The collaboration I've mentioned initially was born when the IQO group realized the periodically poled rubidium-exchanged KTP waveguides that they fabricated had different diffusion depth depending on the poling orientation of its domains.
Different diffusion depth in a waveguide imply a change in the dispersion of light as it goes through it, so we predicted that the light coming out of those waveguides would behave in an unwanted way, by generating two distinct peaks in its phasematching function. This lead to a poor conversion efficiency of the sources.
From home, I've worked on a numerical algorithm that would figure out a customized poling structure that would correct for this error. I have then expanded this algorithm to work with arbitrary dispersion relations in crystals (such as tapers or pink-noise/parabolic shaped waveguides). It wasn't clear that this algorithm was outputting the best solutions to our problem, so we've worked on a more general way to figure out the best poling structure for those waveguides. My supervisor figured out a way to do it analytically in a more reliable way, before I came in.
When I joined the group, I spent a good amount of time trying to catch up with what was being done here, and eventually started working on an algorithm that would give us the optimal poling structure for realistic conditions and variable dispersion relations for different positions in crystals. Research being what it is, we've encountered a couple of problems, which resolution lead us to think that the initial problem was not going to happen exactly the way we predicted it to. We'll be continuing this work remotely and hope to have something to publish about it by the end of this year.
There are differences from everyday working life to Canada?
Again I've got a pretty limited sample to draw conclusions from, but I can certainly say that the group here was far more organized as a team than anything I've seen before. People all work roughly the same hours, eat lunch at the same time together, have regular group activities which I had the opportunity to join, including LANs, board games, climbing and regular dinners. People also spends a lot of time discussing physics, which was unusual (at this level) for me.
What brings your working group in Canada your stay with us in Paderborn?
People here are experts in characterizing waveguides and working with them for different purposes, including as single photon sources. My group's work include characterizing and improving pure single photon sources, so understanding correctly how waveguides physically work in practice is a necessary tool for us.
What brings you personally the stay with us in Paderborn?
I've never been out of Canada before, so it was a massive experience to leave my comfort zone to be in a different country. Discovering a new group and new people who are highly knowledgeable in my field was wonderful. I've also put a face on those people whose papers I've been reading for the past year.
How do you like it in Germany?
I haven't had the opportunity to explore more of Germany yet, and that's something I plan on doing during my last week I'm staying in Paderborn. For Paderborn itself, I can say I was really struck by how differently structured the layout of the city is. It's very different from the usual grid-like structure in Canada. I really like the fact that there's a huge reserved biking road almost everywhere you go. The architecture is also very different, it was amazing to discover.
I can't really speak for the whole population as I've had a restricted sample of them, but the people I've met here and worked with were truly wonderful people. That's one of the main reason I appreciated my time and work experience here. The group was really welcoming and helped me get set up right from the start.
Is there anything that surprised you in Germany? What you have imagined differently?
The fact that everything is closed on Sunday, that people here proportionally eat a lot of pork compared with beef, that dairy products are so cheap, that you have to pack what you purchase at groceries and that peanut butter is so rare and expensive is what struck me the most.
Do you have a tip for other people who would like to join an exchange?
Everything went pretty well for me, so I don't have many solutions to offer. I would say trying to understand how the train system works before coming here would help, to avoid missing a transfer (which happened to me when I got here). Also, trying to get a bike as soon as you get in Germany is something essential.
Dear Jérémy, merci beaucoup for your time and your exciting description!
De rien. That was fun to answer!
