Fabien Kéfélian holds a master's degree (DEA) in optics and photonics from Université Paris - Saclay (2002), an engineer's degree from Ecole supérieure d'optique - Institut d'optique theorique et appliquée (SupOptique, 2002) and a doctorate in electronics and communications from Ecole nationale supérieure des télécommunications, France (2005).
He worked first on diode laser non linear dynamics and noise in Telecom Paris, III-V Lab and Tyndall National Institute. Then he joined the Observatoire de Paris and Université Paris XIII for the first demonstration of ultra-stable optical frequency transfer on internet fiber network. He also developped a new laser stabilisation technique leading to a patent.
After a year as lecturer in Sorbonne Université and researcher in Institut Langevin in holographic Doppler tomography, he joined the VIRGO collaboration in 2011 first in APC laboratory, Université de Paris then in ARTEMIS Lab, Observatoire de la Côte d'Azur. He has been an associate professor in Université Côte d'Azur since 2013.