Siddharth Doshi: Electrically active dynamic nanophotonics

This summer, I had the opportunity to visit the group of Professor Harald Gießen at the 4th Physics Institute (PI4) of the University of Stuttgart and collaborate with them on developing nanoscale optical devices using polymer materials that change their optical properties when a voltage is applied. Our groups have had an ongoing collaboration so it was nice to visit them in person while also getting the chance to experience some authentic culture. 

As part of my visit, I spent a lot of time fabricating and testing photonic devices made from soft polymer materials. PI4 has an excellent nano and microfabrication facility, with a brand new cleanroom and many state of the art tools including electron-beam lithography systems. As someone who has spent a lot of time developing nanofabrication processes as well, it was nice to learn how they do things there and exchange knowledge. Although device-based projects can be hard nuts to crack in the span of a short visit, we made progress on a project to create polymer based photonic devices that can control properties of light such as polarization. I look forward to continuing this work with them beyond the length of the research visit. While there, I also really enjoyed learning about all of their state-of-the-art laser facilities, where they make tricked out custom lasers by leveraging non-linear processes. 

I also really appreciated shooting the breeze with other groups in the surrounding area that also work with polymers and/or nanostructured optical devices. There were other experts just down the road, such as the groups of Laura Liu or Sabine Ludwigs and groups at the nearby Max Planck Institute just down the road. Presenting my PhD research to them was interesting as they provided a range of different perspectives on my work. 

Having spent the last few years in Palo Alto, it was fun to stay right in the midst of a small city, where you could find diverse food and more bars than you can shake a stick at just a few minutes walk away. Stuttgart is the home of Hegel, and they make it known. Visiting lovely old-school towns like Esslingen, Tübingen and Heidelberg, which were just short train rides away, made for nice ways to spend the weekend. 

One of the highlights of the trip was the Gießen group trip in Pfalz for a week, which the group generously took me on. In addition to learning about all the cool science in the group (every group member presented), we went on hikes in the picturesque surroundings where we could chat in a casual environment, before evening sessions by the fire with a few cheeky bevs. I appreciated the culture of robust but respectful debate that the group tried to foster. Professor Gießen was also kind enough to show me around the town of Speyer and their impressive cathedral, a former seat of imperial power. 

Looking ahead, I’m eager to maintain connections with my colleagues in Stuttgart as we continue our collaboration. I plan to analyze the data we collected and analyze device samples we prepared together. Overall, this GRIP supported visit was an extraordinary chance to be immersed in a different work style and culture. I am immensely grateful for the opportunity!