Abstract Body

Temporal and spatial detection of single photons has driven advances in single-photon imaging, fluorescence lifetime analysis, remote optical communication, and quantum information processing. Superconducting nanowire single-photon detectors (SNSPDs) have shown outstanding advantages in terms of efficiency, jitter, and speed. However, limited to the low-temperature environment, it is difficult to read out large-scale SNSPD arrays. Existing readout structures typically separately use dimensionality reduction (row-column architecture), encoding, and feature multiplexing (time or frequency) methods, which are challenging to further reduce readout complexity and increase pixel number. Combined with the strategies of dimensionality reduction and feature multiplexing, we designed an imaging sensor based on time-amplitude two-dimensional joint multiplexing, which can read out 1024 spatial positions with only two readout ports. Furthermore, by exploring the delay-time logic, the resolution of two-photon positions in 16 pixels is successfully realized. The imaging device has the characteristics of strong scalability and high pixel readout fidelity.

References

[1] Kong, L.-D. et al. Readout-efficient superconducting nanowire single-photon imager with orthogonal time–amplitude multiplexing by hotspot quantization. Nature Photonics 17, 65-72 (2023).

Figure 1. Superconducting nanowire two-photon coincidence counter (SNTPC). a, Schematic illustration of the device design and operation principle. b,c,d, A scanning electron micrograph of the 16 detector pixels and partial delay lines.

Keywords: Superconducting nanowire, single-photon imaging, two-photon detection