An on-chip photon-counting device to advance quantum technology

The first realization of an on-chip photon-number-resolving (PNR) detector.

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In quantum information science and quantum sensing fields, single-photon detectors are widely used. They play a critical role in several scientific breakthroughs and necessary quantum optics tests. The best way to measure light is with photon-number-revolving detectors, but only a select few detectors can do so at few-photon levels.

A new study from Yale scientists reports an on-chip detector that can resolve up to 100 photons by spatiotemporally multiplexing an array of superconducting nanowires along a single optical waveguide.

Photon-number-resolving (PNR) detectors are regarded as the most desirable technology for detecting light. Thanks to their exceptionally high sensitivity, they can count the photons in even the weakest light pulses. They are fundamental for various quantum applications, including quantum computing, cryptography, and remote sensing. The number of photons that current photon counting systems can detect simultaneously is constrained, typically only one at a time and not more than ten.

Yiyu Zhou, a postdoctoral associate in Tang’s lab, said, “The problem is that if you have more than one, the detector will be saturated.”

“The device not only advances PNR capability by up to 100 but also improves the counting rate by three orders of magnitude. It also operates at an easily accessible temperature.”

Tang said, “Because of this, the device allows for a broader range of applications, especially in many fast-emerging quantum applications, such as large-scale Boson sampling, photonic quantum computing, and quantum metrology.”

Credit: Yale University

Scientists further plan to integrate the detector with on-chip quantum light sources. Conventional detectors are designed to be interfaced with an optical fiber, which can lead to signal loss. 

Risheng Cheng, a former postdoctoral associate in Tang’s lab and a research scientist at Meta, said“If we can integrate everything, we would have a lower loss and a higher fidelity of measurement.”

Journal Reference:

  1. Cheng, R., Zhou, Y., Wang, S. et al. A 100-pixel photon-number-resolving detector unveiling photon statistics. Nat. Photon. (2022). DOI: 10.1038/s41566-022-01119-3