LEDs could help make microwave amplification by stimulated emission of radiation, commonly known as maser technology, more accessible. With their ability to detect and amplify weak microwave signals while introducing minimal noise, masers have the potential to improve many applications in diverse fields. Although masers were invented in the 1950s, their use has been limited to a few specialized areas due to the complex, expensive conditions under which they are made. Historically, maser production has required a vacuum environment, high magnetic fields, and extremely low temperatures. Organic crystalline materials, used with cylindrical resonators and laser or lamp pumping, have enabled the development of masers that run at room temperature, but issues with cost and complexity remain. LED-pumped maser experimental setup and simulation of pump intensity profile. Courtesy of Communications Engineering (2025), DOI: 10.1038/s44172-025-00455-w. A team at Northumbria University, in collaboration with the Université Paris-Saclay, the University of Urbino, and Imperial College London, has developed an alternative pumping system, based on LEDs, that could lower the cost and improve the efficiency of masers. The LED-based system minimizes thermal loads in the gain medium, compared to laser pumping, and ensures sufficient spectral overlap and photon density to drive quantum transitions in the gain medium. The LED-pumped maser could offer a pathway to more durable, compact, affordable masers to use, for example, in quantum computing, atomic clocks, magnetic resonance imaging, and radio astronomy devices for deep space exploration. “By replacing complex laser systems with low-cost LEDs, we have opened the door to practical masers that can operate at room temperature, unlocking exciting potential in quantum technologies, secure communications, deep-space exploration, and portable sensing,” professor Juna Sathian said. The solid-state, LED-pumped maser uses pentacene-doped para-terphenyl (PcPTP) as the gain medium and functions at a frequency of about ~1.45 GHz with a duration of 200 µs. The LED output is integrated with the gain medium via a cerium-doped yttrium aluminium garnet (Ce:YAG) luminescent concentrator, eliminating the need for complex optical alignment. The microwave output power of the maser can attain a maximum of 0.014 mW. The output power achieved with the LED-pumped Ce:YAG system surpasses that of a flashlamp-pumped system by about 2.3x for a transverse pumping configuration and about 4.4x for a longitudinal pumping configuration. The LED-pumped luminescent concentrator ensures both high power and a high pumping rate due to the concentration effect in Ce:YAG. Additionally, the the LED-pumped maser operates at low voltage and intensity, making it safe to use. Professor Juna Sathian led an all-women team of researchers to explore the use of LEDs to create affordable, energy-efficient, room-temperature masers that could be used in quantum technologies, deep-space communications, and portable sensing devices. From left: Bethan Ford, Sophia Long, and Sathian. Courtesy of Northumbria University. By removing the need for high-power lasers and flashlamps, LEDs simplify maser design and operation, making room-temperature maser technology suitable for applications that need to be both scalable and cost-effective. Additionally, the long operational lifetime and precise control that LEDs provide could enable future improvements in energy efficiency, performance stability, and cost. “This is just the beginning,” Sathian said. “The future of maser research lies in developing compact, scalable systems that can be integrated into next-generation quantum and photonic platforms.” The researchers are working to extend the LED-based maser technology into new materials, broader frequency ranges, and real-world applications that will take masers from the laboratory into everyday use. “LED-pumped luminescent concentrators promise a bright future as new sources combining power and brightness,” professor François Balembois said. “We are proud to contribute to the emergence of LED-pumped maser.” The research was published in Communications Engineering (www.doi.org/10.1038/s44172-025-00455-w).