Inline quantum measurements with SNSPDs coupled to photonic bound states
Year: 2025
Type: article
Abstract: We report the realization of inline quantum measurements with waveguide-integrated superconducting nanowire single-photon detectors (SNSPDs). To suppress parasitic scattering at detector terminations, while ensuring compatibility with standard photonic substrates and cryogenic operation, we developed a photonic bound state in the continuum (BIC) platform based on etchless polymer waveguides. We show BIC-coupled inline detectors with on-chip efficiency exceeding 80%, recovery time of less than 2 ns, and intrinsic jitter of less than 70 ps. As a proof of principle, we implement Hanbury Brown and Twiss interferometry and photon-number resolution with two collinear detectors within a footprint of 60 × 6 µm 2 . The concept of inline quantum measurements could be further developed to support more complex circuit functionalities, such as higher-order correlation measurements, quantum state tomography, and multi-photon subtraction, within a compact architecture.
Source: Optica Quantum
Authors: Filippo Martinelli, Anton N. Vetlugin, Shuyu Dong, Darren M. Z. Koh, Mariia Sidorova, Christian Kurtsiefer, Cesare Soci
Language: English
Topic: Photonic and Optical Devices
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
Awards: G3871194215, G5932570315, G6091188921
OpenAlex ID: W4416996228