Finding the 'quantum needle' in a haystack: New filtering method can isolate photons

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.