NIST Researchers Supersize Quantum Technology to Help Detect Faint Photons

In this illustration, photons hit a strip of superconducting wire, disrupting the electric current and registering an electric pulse. Each pulse tells researchers about the light that has hit the detector, which is beneficial for applications like biomedical imaging and astronomy.

Our everyday life is flooded with photons, the quantum building blocks of light. For cutting-edge technology, from quantum computing to deep-tissue imaging, detecting every single photon counts.

“Photons carry information,” said Kristen Parzuchowski, a postdoctoral researcher at the National Institute of Standards and Technology. “Whenever a photon comes into your measurement system, you need to be able to detect it.”

Photons can transmit data in quantum networks or across deep space communication links. Catching and analyzing photons lets scientists build biomedical images and search the universe for dark matter. 

Superconducting nanowire single-photon detectors (SNSPDs) are the best way to capture photons for all these applications. As their name implies, they use the phenomenon of superconductivity, in which electricity flows without resistance, to detect individual photons. Single particles of light create tiny splashes in the electric current, which disrupt the superconductivity and trigger a measurable electrical signal. NIST has drastically improved these devices over the years to the point at which they detect 98% of the photons that come in.