Interview with Rachel Grange
INTERVIEW
Interview with Rachel Grange
© Kilian Kessler / ETH Zurich
Professor at ETH Zurich, expert in optical nanomaterials, nonlinear optics and integrated photonics.
https:// doi. org / 10.1051 / photon / 202513413
During your early years, when did science become meaningful to you? I think back to that critical age between 12 and 15, when you are already asked to pick a high-school track. I chose Latin because I loved history and French, I read a lot. I didn’ t have a scientific heroine; my“ heroes” were athletes, especially the Swiss-German skiers winning all the medals, and even a Swedish skier who was incredibly strong. I don’ t come from a scientific family, but I loved visiting my father’ s mechanical workshop, where he repaired trucks. That hands-on, practical side of things fascinated me. I already liked the idea of“ doing” science.
How did you end up specializing in physics? In high school there was a reinforced math and physics track, I took it. Physics was exciting but very abstract. A math teacher from high school showed us mathematics from a useful angle, such as probability, statistics, and conics, which convinced me that at EPFL, science would be concrete and useful. I chose physics more for the challenge than out of a calling. I considered moving to the German-speaking part of Switzerland, but adding a language barrier on top of the difficulty of physics felt like too much. So I chose EPFL in Lausanne, in the French-speaking region. I also liked chemistry and almost ended up there, but on the open day, after visiting the physics section, I stopped to chat at the café and never made it to chemistry!
How long was the training at EPFL? It was still the diploma system, four and a half years. First, two propedeutic years, like an accelerated preparatory cycle; then two and a half years with more specialized courses, either theoretical or applied physics, and the diploma project. EPFL remained fairly generalist, which suited me. I took everything experimental and avoided overly abstract classes.
Where do optics and materials come in? We often start with optics in high school, sometimes even before mechanics. At EPFL I wanted something practical, so a teaching assistant helped me get into a lab where I worked on some of the first multicore fibers, measuring their polarization. That’ s when optics really took hold for me, and it never left. I also hesitated about nuclear physics. The campus has a mini-reactor for lab classes, and seeing fuel rods up close is impressive. The broader energy debate convinced me we needed good physicists to avoid disasters.
How did the move to Zurich for your PhD happen? I graduated at the end of 2001, with the formal certificate in February 2002, wanted to do a PhD, and thought learning German would help a career in Switzerland. I applied to Ursula Keller’ s group because I liked the topic and because she was a woman leading the lab, something I had never experienced. My PhD focused on semiconductor saturable absorber mirrors( SESAMs). I didn’ t grow the materials, colleagues did the epitaxy, but I handled the design, clean-room processing, and linear and nonlinear optical characterization. The group pursued record-setting lasers at telecom wavelengths and titanium-sapphire. I built and ran the setups to measure recovery time and saturation fluence for passive modelocking, a SESAM replacing a mirror with a Bragg stack plus absorber. I started in March 2002 and defended in March 2006. What were your expectations after your PhD defense? I had poured so much into the lab that I needed to step back. Despite good conditions, I was burned out and had never dreamed of becoming a professor. My husband was finishing his medical specialty, and I didn’ t want to leave Switzerland at that time. I looked for a job in industry, but the telecom sector was in crisis, and my applications didn’ t pan out. I even tried the patent office. I then joined the Swiss State Secretariat for Education and Research, working a year and a half on research policy and OECD indicators. It was interesting, but I missed the lab within six months.
What brought you back to the lab? Colleagues told me that Demetri Psaltis had moved from Caltech to EPFL as dean. I thought,“ Caltech comes to me,” and it seemed the perfect opportunity to work in an international group without moving to the US. That is why I joined his lab as a postdoc in nonlinear optics and microfluidics. It was a great topic after my PhD because it bridged laser-building and laser-enabled applications. We set up new labs with equipment arriving from Caltech, bought an optical table, restarted old titanium-sapphire lasers. A small team of three to four people worked very efficiently. I stayed about three years, around 2007 to 2010, and two children were born during that time. I had always received a great support from my supervisor. The
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