On-chip detection of non-classical light by scalable integration of single-photon detectors

• Published in: Nature communications Vol. 6; no. 1; p. 5873
• Main Authors: Najafi, Faraz, Mower, Jacob, Harris, Nicholas C., Bellei, Francesco, Dane, Andrew, Lee, Catherine, Hu, Xiaolong, Kharel, Prashanta, Marsili, Francesco, Assefa, Solomon, Berggren, Karl K., Englund, Dirk
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 09.01.2015; Nature Publishing Group; Nature Pub. Group
• Subjects: 142/126; 639/624; 639/766/1130/2799; 639/766/25; 639/925/927; Computer engineering; Electrical engineering; Humanities and Social Sciences; Information science; Integrated circuits; Light; multidisciplinary; Nanowires; Science; Science (multidisciplinary); Semiconductors; Sensors; Silicon nitride; New York; California; United States > US; Massachusetts
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms6873

Photonic-integrated circuits have emerged as a scalable platform for complex quantum systems. A central goal is to integrate single-photon detectors to reduce optical losses, latency and wiring complexity associated with off-chip detectors. Superconducting nanowire single-photon detectors (SNSPDs) are particularly attractive because of high detection efficiency, sub-50-ps jitter and nanosecond-scale reset time. However, while single detectors have been incorporated into individual waveguides, the system detection efficiency of multiple SNSPDs in one photonic circuit—required for scalable quantum photonic circuits—has been limited to <0.2%. Here we introduce a micrometer-scale flip-chip process that enables scalable integration of SNSPDs on a range of photonic circuits. Ten low-jitter detectors are integrated on one circuit with 100% device yield. With an average system detection efficiency beyond 10%, and estimated on-chip detection efficiency of 14–52% for four detectors operated simultaneously, we demonstrate, to the best of our knowledge, the first on-chip photon correlation measurements of non-classical light. The integration of single-photon detectors, as superconducting nanowire single-photon detectors, in photonic-integrated circuits is a goal of quantum information science. Here, Najafi et al. introduce a micrometer-scale flip-chip process enabling such a integration in a scalable way.