High Dynamic Range Superconducting Nanowire Single Photon Detectors

Superconducting nanowire single-photon detectors (SNSPDs) play a prominent role in sparse photon detection, but they tend to exhibit latching or saturation issues when confronted with high flux photons, which is commonly observed in applications such as deep space communication, LiDAR and passive imaging. Therefore, expanding the dynamic range of SNSPDs becomes indispensable. Inspired by the photoreceptor cells on human retina, this study conducted a biomimetic design of SNSPDs. The arrangement of pixels imitated the distribution of cone and rod cells, and the photosensitivity of these two different cells to the incident photons was altered by adjusting parameters such as linewidth, polarization, photosensitive area, and bias current. This design significantly enhances the overall dynamic range of the device, facilitating a linear response to incident photon flux ranging from 10³ photons/s to 1.16×10¹⁴ photons/s, and the dynamic range is 110.64 dB. Furthermore, imaging experiments using digital micromirror device (DMD) were performed to simulate high dynamic scenes. Combined with compressive sensing single pixel imaging strategy, imaging of incident light within a 90 dB range was achieved, demonstrating the functionality of the device over an extremely wide dynamic range.

I. Introduction

Superconducting nanowire single photon detectors (SNSPDs) have achieved outstanding performance in both visible and near-infrared wavelengths with system detection efficiency (SDE) higher than 95% [1], [2], timing jitter on the order of a few ps [3], and negligible dark counts as low as 10⁻³ cps [4]. These merits render SNSPDs crucial in quantum information fields [5], [6], [7] and faint signal detecting scenarios [8], [9], [10]. However, despite their remarkable capability in detecting sparse photons, SNSPDs can encounter operational challenges when exposed to sudden fluctuations in photon flux density. Notably, at extremely high photon flux, SNSPDs may suffer from latching, where the device experiences an irreversible transition from the superconducting state to the resistive state, or count rate saturation, where the detector reaches its maximum count rate (MCR) and begins to lose sensitivity to additional incoming photons. This is indeed mainly attributed to the inherently restricted dynamic range of present-day SNSPD designs, which hampers their capacity to precisely and consistently detect photons under highly variable light intensity conditions [11].