The Hybrid Photonics Lab in the School of Engineering has published a new paper describing a compact laser that uses a voltage-controlled metasurface to achieve ultrafast tuning.Led by PhD student Zahra Basiri and HYLAB head Cristina Benea-Chelmus, the team developed a semiconductor laser that uses an electro-optic metasurface as an external mirror. The design enables rapid and precise wavelength and intensity control, without moving parts or bulky external components.Unlike conventional tunable lasers, which often rely on changes in temperature or mechanically moving components to adjust their output, the new design achieves tuning electronically through the metasurface. This allows the laser to respond much faster, while remaining compact and robust.In addition to electronic tuning, the metasurface keeps the laser operating at a single, stable wavelength, avoiding the abrupt jumps (mode hops) that often affect tunable lasers. At the same time, a small voltage allows the laser frequency to be adjusted extremely rapidly, at rates of up to 180 terahertz per second, while maintaining stability and precision.2026 HYLAB/EPFL - CC BY SA 4.0“Our results establish electro-optic metasurfaces as a powerful route toward compact, high-speed, mode-hop-free tunable lasers for free-space communications, ranging, and high-resolution spectroscopy,” says Basiri, who is lead author on the paper published in Science Advances.“Metasurfaces have long been appreciated for their ultracompact form factor and light weight. At the same time, there is a strong trend in miniaturizing free-space lasers,” adds Benea-Chelmus. “We’ve been dreaming about bridging these two fields to provide control over laser emission for a long time now, and seeing this happen at ultrafast speeds in our lab at EPFL is very exciting!”ReferencesZahra Basiri et al. Metasurface-controlled high-speed tunable external cavity lasers.Sci. Adv.12,eaee1791(2026).DOI:10.1126/sciadv.aee1791