A new device developed in South Korea can generate individual particles of light at room temperature, without the massive cooling systems that have long kept this technology confined to research laboratories. The Korea Research Institute of Standards and Science, known as KRISS, built the device into a standard 19-inch rack-mounted unit that powers on and works immediately, according to a report by Phys.org. The study was published in the journal Laser and Photonics Reviews.
Single-photon sources generate photons one at a time. They form the foundation of photon-based quantum technologies including quantum communication, quantum sensing, and quantum measurement. In quantum communication, information is encoded onto individual photons, and any attempt at eavesdropping alters the photon's state, leaving a detectable trace.
Until now, devices capable of doing this required cryogenic temperatures of around -270 degrees Celsius, room-sized optical tables, and skilled researchers to operate them. Those requirements made it nearly impossible to deploy the technology in real-world settings such as communication sites, hospitals, and security facilities.
The KRISS device is built around a gallium nitride semiconductor. Tiny defects that form naturally inside the material emit photons one at a time when energy is applied to them. The challenge has been that these defects are atomic in scale and scattered randomly, making it difficult to return to the same emission point after the device is switched off.
To solve that problem, KRISS developed a deterministic spatial mapping technique that records each emission site like a set of coordinates. The device can then return automatically to the same point the next time it is powered on. That capability is what makes the plug-and-play operation possible.
A research team led by Professor Lee Wook-Jae at Kongju National University, a collaborating partner on the project, designed and fabricated nanometer-scale circular Bragg gratings on the surface of the semiconductor. These structures guide photons upward and maximize how efficiently photons are extracted from the defects inside the material.
The finished device runs on a standard 220-volt power supply. Its rack-mount form factor is designed to connect directly with existing quantum key distribution equipment, which is used to secure communications using quantum mechanics. That compatibility makes the device practical for installation at real communication sites, not just in controlled laboratory conditions.
KRISS described the achievement as a case of domestic localization of quantum materials, parts, and equipment. As competition among nations to establish early leads in quantum technology grows, securing the ability to build core components domestically has become a priority. South Korea's push to develop home-built quantum hardware fits into that broader race, and the new device represents a concrete step toward field-deployable quantum infrastructure.
The research points toward a future where quantum communication systems could be installed in hospitals, government facilities, and secure networks without requiring specialized staff or exotic cooling equipment to keep them running.
