Quantum cascade laser frequency combs: physics and applications (Prof. J. Faist)

Recently, we have shown that such broadband devices, when operated in continuous wave, emit as a coherent optical comb1 in which the phase relation between the comb modes corresponds approximately to a FM modulated laser2. More recently, by measuring the GDD of the device and correcting for it using dedicated coatings, record power levels (120mW) and comb stabilities have been achieved. We have also recently shown that these combs can also be produced in the THz region of the spectrum, with the gain bandwidth covering a full octave. These new comb lasers enables the fabrication of a dual comb spectrometer based on a quantum cascade laser that offers a broadband, all solid-state spectrometer with no moving parts and a ultrafast acquisition time. We demonstrate a spectrometer and its first proof-of-principle applications, as well as new integrated dual-comb devices.   

References:
1. A. Hugi, G. Villares, S. Blaser, H. C. Liu and J. Faist, Nature 492 (7428), 229-233 (2012).
2. J. B. Khurgin, Y. Dikmelik, A. Hugi and J. Faist, Applied Physics Letters 104 (8), 081118 (2014).
3. A. Hugi, S. Blaser, G. Villares, and J. Faist, Nature Communications, vol. 5, pp. 1–9, Oct. 2014.

On the person:
Jérôme Faist obtained his Diploma and Ph.D. in Physics (1989) from EPFL. After working at IBM Rueschlikon (89-91) and Bell Laboratories (91-97), he was nominated full professor in the physics institute of the University of Neuchâtel (1997) and then ordinary professor in the ETH Zurich (2007). His key contribution to the development of the quantum cascade laser was recognized by a number of awards that include the IEEE/LEOAS William Streifer award (1998) the National Swiss Latsis Prize 2002. His present interests cover Quantum cascade laser frequency combs and the physics of the ultrastrong coupling regime.