Interview: Dalziel J. Wilson
Hi Dal, you are currently working as a scientist in the Kippenberg group at the EPFL. What is the main focus of your research?
We study optomechanics, which deals with the measurement and control of mechanical objects with light. Our speciality is coupling nanomechanical resonators to optical microcavities. These devices are so sensitive that we can manipulate a single quantum of mechanical motion (a phonon) with a single photon.
How will the sensors you are exploring influence our lives?
Well, on one hand, nanomechanical resonators are a key component of precision mass and force sensors. Figuring out how to manipulate nanomechanical motion with greater precision may help, for example, improve the resolution of an atomic force microscope to the level of single nuclear spin, or the resolution of a mass spectrometer to single atoms/molecules. This would have pleasant consequences for biomedical and material science. Cavity optomechanical systems also enable mechanical resonators to be used for measurement and frequency conversion of light, from RF to microwave to optical domain. This has obvious appeal to the telecommunications industry. My favorite "application", though, is gravity-wave astronomy. If we can realize ultra-precise, long baseline position measurements (namely, if we can resolve the distance between km-separated objects to a precision 1000 times smaller than a proton in roughly 1 second), then we ought to see the world "shaking" due to small ripples in spacetime called gravity waves. These waves are produced by violent cosmological events like the collisions of black holes, and - if we could detect them - would open an whole new window into the universe... It's been more than 20 years, though, and we still haven't measured one!
How does our instrument help you achieve your results?
Most of what we do in the lab is RF noise spectroscopy. In particular, we study the Brownian motion of small mechanical resonators. These are multimode resonators with frequencies in the range of 100 kHz to 100 MHz, and with bandwidths as narrow as 1 Hz. The frequency flexibility of the UHFLI comes in handy for a variety of bread-and-butter tasks. Currently we like the UHF-DIG Digitizer option for taking broad, high density FFTs. We also use the UHFLI for ringdown measurements (in this case we employ it as a lock-in). In the future we plan to use it for cross-correlation measurements and feedback control. It's of course very appealing to have these capabilities integrated into a single box.
When did you come to Switzerland and how did you adjust to your life here?
I came to Switzerland in July of 2013. I'm still adjusting. I find that it helps to spend a least one day per week in the Alps.