Researchers are developing increasingly sophisticated sources of entangled photons for applications in quantum communication and sensing. Keshav Kapoor, Dong Beom Kim, and Kriti Shetty, all from the University of Illinois Urbana-Champaign, alongside Virginia O Lorenz and colleagues at the same institution, have demonstrated a novel photon-pair source fabricated within commercially available optical fibre. This device generates paired photons at both near-infrared and telecommunication wavelengths, specifically separated by 700nm, offering a significant advantage by minimising Raman noise and achieving a high coincidence-to-accidental ratio at room temperature. The source’s unique ability to produce spectrally distinct, phase-matched processes, combined with its use of…