What are you working on at the moment?
Our group is working on transducers, in particular the link between optical and electronic elements. We are interested in free-space applications, such as LIDAR technology, in ultra-fast imaging, in augmented reality, as well as in on-chip systems important for high-frequency communication. We are investigating the whole process, from signal generation to metrology, so we aim at measuring terahertz signals in the quantum regime. For this, you need to be able to measure small signals precisely, which is where Zurich Instruments’ lock-in amplifiers enter the picture.
Please tell us about your journey as a scientist up to now.
I did my undergraduate studies at the Karlsruhe Institute of Technology in Germany – a bachelor’s degree in Electrical Engineering and a master’s in Optics and Photonics. During my studies I had the opportunity to go to EPFL as an ERASMUS exchange student. For my master’s thesis, I went back to Switzerland and joined the group of Jerome Faist at ETH Zürich, where I then continued with a PhD in physics focused on terahertz photonics. After a postdoc at Harvard, I came back to EPFL as a tenure-track assistant professor at the Institute of Electro and Microengineering. I enjoy working on engineering challenges while delving into the physics of how things work.
What is the most fun aspect of your job, and what is the biggest challenge when starting a new group?
It’s great fun to build things from scratch: everything is very chaotic at the beginning, but it’s nice to see how things develop. I also enjoy interacting with students and seeing how they acquire new skills. The challenging part is to understand all individual parts in-depth to make sure that all ends meet and that we have a functioning experimental setup in the end.
Can you tell us more about how you use the UHFLI in your lab?
We use the UHFLI Lock-in Amplifier for many types of measurements, for example to characterize our electro-optical modulators. For this we need high frequencies, typically around several hundreds of megahertz or even up to several gigahertz. To reach the gigahertz regime, we generate I/Q signals with the UHFLI and then upconvert them with an external mixer and a microwave source. A consequence of working in the gigahertz regime is that we pick up a lot of noise from the environment - from wifi connections, for instance. This is the reason why we use double modulation schemes where we characterize the sidebands with the UHFLI, leading to a huge improvement of the signal-to-noise ratio.
The LabOne software is also of great help in our experiments, because we can use all the analysis tools, such as the Scope and the Spectrum Analyzer, as we run a measurement. Plus, it’s nice to be able to talk to an application scientist whenever help is needed in the lab.
What do you like to do in your free time?
I love mountain sports and windsurfing. I hope to be able to catch some nice winds in Lausanne – in terms of research but also at the shore of the lake.
