The University of Twente has made a groundbreaking discovery in the field of photonics, achieving a 100x brighter UV light on a chip. This achievement is a significant leap forward in the development of integrated photonics, with potential implications for quantum computing and optical atomic clocks. The team, consisting of researchers from the University of Twente and Harvard University, utilized thin-film lithium niobate to create a nearly two-centimetre long waveguide, which precisely channels light and enables the conversion of two red photons into a single UV photon. This process, detailed in Nature Communications, marks the first instance of producing a useful amount of UV light, several milliwatts, integrated onto a single chip. The precision required for this fabrication process is remarkable, with each of the approximately 10,000 electrodes along the waveguide tailored to within fifty nanometres across the chip’s length. This level of control and accuracy is crucial for manipulating light at the nanoscale and reversing the material’s crystal structure periodically, up to a thousand times per millimetre. The resulting milliwatt-level UV light represents a substantial improvement over previous attempts, delivering roughly a hundred times more output. The team's approach, positioning electrodes directly on the waveguide, demands a highly refined fabrication process, and the underlying knowledge is now housed within UT spin-off Sabratha. This breakthrough has the potential to shrink and improve technologies ranging from quantum computers to optical atomic clocks, and it opens doors for practical applications beyond mere trace detection. The use of thin-film lithium niobate as a waveguide material is gaining prominence for its unique properties, allowing for precise manipulation of light at the nanoscale. This achievement is a significant step towards the realization of integrated photonics, with the potential to revolutionize various technologies and applications.
