Interview: Marcos Dantus
Marcos, many thanks for taking the time to talk to us. You’re well known as a leader in the use of ultrafast lasers, but how did it all start?
Well, I actually started studying Chemical Engineering, but it was soon clear to me that I wanted to look deeper into the science and I was also interested in instrument design. So, I decided to move to Brandeis University up in Boston, where I studied Chemistry. My interest in lasers started there too, when I was studying for my masters.
What was the next step?
While looking for a PhD opportunity, I interviewed with Ahmed Zewail at Caltech and I realized he had very exciting ideas. I joined his group and within a year I was involved in the design and construction of the first laser lab to study chemical reactions with femtosecond (fs) time resolution, now known as Femtochemistry. At that time, it seemed like everything we did with lasers was a major breakthrough (Professor Zewail was later the recipient of the 1999 Nobel Prize in Chemistry for his pioneering developments in femtoscience). I stayed on with the group for my Postdoc and we came up with a combined laser and electron diffraction system, enabling us to track chemical structures with fs resolution.
You next moved to Michigan State University (MSU). How did that come about?
Well, when I was looking for a permanent position after my time as a Postdoc, MSU made me an offer that I could not refuse. Looking back MSU has been a great place for me, both professionally and personally. I’ve been lucky enough to get really good quality students and Postdocs, plus I’ve been able to establish key collaborations to advance our research.
I’ve also been involved with a number of start-ups during my time here, and the university has been very supportive: KTM Industries manufactures “green” packaging materials, Total Power Inc. develops and manufactures fuel additives, Biophotonic Solutions, which was acquired by IPG Photonics a couple of years ago, offers ultrafast pulse shaping optics and software. The latest startup makes sensors to detect possible concussive impacts in young athletes - ROSHsensors.com.
Tell us about your current research areas.
It’s broken down into a couple of themes. In terms of fundamental research, I’m interested in chemical reactions under extreme conditions, in our case using high-intensity lasers with peak powers of 1015 W/cm2 or more. We look at what happens to structure and functional groups, and focus on hydrogen atom and molecule migration on the fs timescale.
We’re also looking at superphotoacids and superphotobases and their behavior on fast timescales. This is of interest for some solar energy applications.
In addition to this fundamental research, I’m interested in more applied research such as biomedical imaging and standoff detection of explosives.
How do you choose your research areas? Do you look to follow the current trends?
I would say that I’m something of a contrarian and avoid what everybody else is doing. I like big challenges and if I see a gap in a particular area that I think I can address then I go for it. An example would be in standoff detection – I looked at what people were proposing and I thought that there were aspects of the problem that were being missed. I’m certainly not one for following trends!
Looking ahead, I’m intrigued by machine learning. I believe that this is going to have a big impact on science and will have an influence on my fundamental and applied projects. An example is pulse shaping, where a computer-controlled fs pulse shaper could “know” what you want to do. I’ve already started on some collaborations in this machine learning area.
So what advice do you have for academics and other scientists at an earlier stage in their career?
Well, first of all, you must really enjoy what you’re doing. Also, remember that every day can bring a new idea and you can be creative – few jobs or careers offer you that intellectual freedom.
There’s also a maxim that I think everyone will find useful – “there are times to work hard and times to work smart.” Working hard makes the difference between good and excellent, but working smart makes the difference between being evolutionary and revolutionary.
How did you find Zurich Instruments and the UHFLI/Boxcar combination in particular?
Like everyone else, I saw your adverts in Physics Today. I saw that the UHFLI operated at 600 MHz and my first response was “that’s pretty amazing!” I then saw it at CLEO and was intrigued, I got a much better sense of what it was. It certainly wasn’t just a lock-in but at the time I didn’t have an application for it.
A little later I was under pressure to produce results for a standoff detection project, where I had a 2 MHz laser and needed to measure stimulated scattering to determine whether we had a loss or gain compared to a reference pulse. Now for standoff detection, there can be all sorts of samples, it’s not a “lab setup” with a cuvette; every pulse needs to be compared with a reference. Once we’d figured out what was needed we had a reason to buy a UHFLI – specifically for the high-speed boxcar capability.
We contacted Zurich Instruments and explained what we needed. We didn’t want just a fast digitizer, as we’d have to deal with all the post-processing of data. What we wanted to do was measure two channels simultaneously, subtract the background signal from both, get the difference between them, average 4 or more pulses, send that number at hundreds of kHz to a PC for mapping as the laser scanned. Your Application Scientists were able to confirm that we could do this.