In quantum technologies, everything depends on the ability to detect the properties carried by a single photon. But in the real world, that photon of interest is often buried in a sea of unwanted light—a true “needle in a haystack” challenge that currently limits the deployment of many applications, including secure quantum communication, quantum sensors used in telescope networks, as well as the interconnection of quantum computers to accelerate the development of new drugs and materials.

At the Institut national de la recherche scientifique (INRS), the team of Professor José Azaña, in collaboration with Professor Roberto Morandotti’s group, has developed a surprisingly simple and energy-efficient way to overcome this obstacle. The work was carried out by Benjamin Crockett during his Ph.D. at the INRS Énergie Matériaux Télécommunications Research Centre. He recently completed his degree and is now a Banting postdoctoral fellow at the University of British Columbia (UBC).

Their method not only reduces noise but, more importantly, recovers essential quantum properties that would otherwise be lost in bright environments where current technologies fail.