Scientists at the U.S. Naval Research Laboratory (NRL) and the Air Force Research Laboratory (AFRL) have developed a way to directly write quantum light sources, which emit a single photon of light at a time, into monolayer semiconductors such as tungsten diselenide (WSe2). Single photon emitters (SPEs), or quantum emitters, are key components in a wide range of nascent quantum-based technologies, including computing, secure communications, sensing and metrology.