We present single-photon counting pixels realized by the monolithic integration of superconducting-nanowire single-photon detectors with Josephson electronics. These pixels are scalable to large-format sensor arrays and are compatible with CMOS array readout architecture.
Abstract We demonstrate superconducting single-photon detectors (SPDs) that integrate signals locally at each pixel. This capability is realized by the monolithic integration of superconducting-nanowire SPDs with Josephson electronics. The motivation is to realize superconducting sensor elements with integrating capabilities similar to their CMOS-sensor counterparts. The pixels can operate in several modes. First, we demonstrate that photons can be counted individually, with each detection event adding an identical amount of supercurrent to an integrating element. Second, we demonstrate an active gain control option, in which the signal added per detection event can be dynamically adjusted to account for variable light conditions. Additionally, the pixels can either retain signal indefinitely to record all counts incurred over an integration period, or the pixels can record a fading signal of detection events within a decay time constant. We describe additional semiconductor readout circuitry that will be used in future work to realize scalable, large-format sensor arrays of superconducting SPDs compatible with CMOS array readout architectures.
We designed, fabricated, and tested a one-dimensional array of superconducting-nanowire single-photon detectors, integrated with on-chip inductors and resistors. The architecture is suitable for monolithic integration on a single chip operated in a cryogenic environment, and inherits the characteristics of individual superconducting-nanowire single-photon detectors. We demonstrated a working array with four pixels showing position discrimination and a timing jitter of 124 ps. The electronic crosstalk between the pixels in the array was negligible.
Superconducting nanowire single-photon detectors (SNSPDs) have emerged as essential devices that push the boundaries of photon detection with unprecedented sensitivity, ultrahigh timing precision, and broad spectral response. Recent advancements in materials engineering, superconducting electronics integration, and cryogenic system design are enabling the evolution of SNSPDs from single-pixel detectors toward scalable arrays and large-format single-photon time tagging cameras. This perspective article surveys the rapidly evolving technological landscape underpinning this transition, focusing on innovative superconducting materials, advanced multiplexed read-out schemes, and emerging cryo-compatible electronics. We highlight how these developments are set to profoundly impact diverse applications, including quantum communication networks, deep-tissue biomedical imaging, single-molecule spectroscopy, remote sensing with unprecedented resolution, and the detection of elusive dark matter signals. By critically discussing both current challenges and promising solutions, we aim to articulate a clear, coherent vision for the next generation of SNSPD-based quantum imaging systems.
We present the development of key technologies for realization of superconducting nanowire single photon detector array system, which enables high counting rates, and allow spatial and pseudo photon number resolution. Toward the realization of practical large-scale SSPD array system, primary issue is how to avoid heat flow into cryocooler system. One of the challenging tasks is the development of their readout electronics. In the conventional readout technique used for single pixel devices, the number of high-frequency coaxial cables increases proportionally with the number of arrays. This causes a significant increase in the heat load from room temperature, which makes the implementation of the SSPD arrays in a compact refrigerator difficult. To overcome this problem, we proposed applying readout electronics with superconducting single-flux-quantum (SFQ) logic circuitsWe show the implementation and successful operation of four pixels SSPD array connected to SFQ readout electronics with parallel bias scheme in a 0.1W GM cryocooler system.