No one enjoys having to repeat themselves as it takes time to do so. The same is true of technology, including future photonic and quantum communication devices, which is why researchers have been working to develop single-photon detectors. Those at Karlsruhe Institute of Technology have recently created a new detector with a detection efficiency of 91%; a new record.
Detecting single photons is not easy as the particles are quite small and there are a multitude of phenomena that can disrupt such a signal. For example, detectors that are connected to silicon chips via fiber optics can actually have photons lost within the optical cable. This new design however is built directly on top of a silicon photonic chip though. The chip holds a nanophotonic waveguide to collect photons and has superconducting nanowires above it. Usually the wires will conduct without electricity, but when a photon is absorbed by the wire, it loses its superconductivity, which can be detected.
By fitting all of the components onto a piece of silicon, the new detector is very small, which will enable hundreds of them to be built into a single chip. Such chips will be needed for optical quantum computers to become a reality.