Quantum cascade lasers and frequency combs: towards chip-based optical chemical sensors

IMT Distinguished Lecture

Abstract: The mid-infrared and terahertz spectral range is key to many applications for sensing and imaging, as many molecules have their fundamental vibration modes in that frequency region. Using traditional multipass cells and single frequency quantum cascade lasers, detection of light molecules with sup-ppb sensitivity and isotopic selectivity has been achieved. There is a strong interest in extending these results to multiple gases and to miniaturized, portable systems.  Towards this goal, the recent demonstration of comb operation in quantum cascade lasers opens up new avenues for broadband spectroscopy. We recently demonstrated a comb device delivering 1 watt of optical power over a bandwidth of more than 100cm^-1 at 8um wavelength. These devices were achieved by engineering the waveguide dispersion using plasmonic resonances.

Bio: Jérôme Faist obtained his Diploma and Ph.D. in Physics (1989) from EPFL. He then worked  at IBM Rueschlikon (89-91) and Bell Laboratories (91-97). It is during that time that he made the key contribution to the invention and further development of the quantum cascade laser (QCL). He was then nominated full professor in the physics institute of the University of Neuchâtel (1997) where his research on QCL enabled to demonstrate the first room temperature, continuous wave operation of a QCL as well as important milestones in the development of THz QCL. Continuing his research as an ordinary professor in the ETH Zurich (2007), his interests broadened to circuit-based THz lasers, ultrastrong light-matter coupling as well as QCL optical frequency combs, which his group demonstrated first in 2012.  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. He is the recipient of an advanced ERC grant in 2013. He is member of APS and a fellow of the Optical Society of America.