TUM develops single-photon sources for quantum communication
Researchers at the Technical University of Munich and the Munich Center for Quantum Science and Technology have developed a new method for single-photon sources based on photonic crystal waveguides that block unwanted light frequencies instead of amplifying desired ones. Initial experiments using erbium as the photon source increased the proportion of desired photons in emitted light from about 23% to around 72%, achieving results comparable to more complex resonator approaches while enabling slower photon generation that better preserves photon properties. The method allows multiple emitters and customizable frequencies within a single device, advantages unavailable with traditional resonators.