Scaling waveguide-integrated superconducting nanowire single-photon detector solutions to large numbers of independent optical channels

Abstract

Superconducting nanowire single-photon detectors are an enabling technology for modern quantum information science and are gaining attractiveness for the most demanding photon counting tasks in other fields. Embedding such detectors in photonic integrated circuits enables additional counting capabilities through nanophotonic functionalization. Here, we show how a scalable number of waveguide-integrated superconducting nanowire single-photon detectors can be interfaced with independent fiber optic channels on the same chip. Our plug-and-play detector package is hosted inside a compact and portable closed-cycle cryostat providing cryogenic signal amplification for up to 64 channels. We demonstrate state-of-the-art multi-channel photon counting performance with average system detection efficiency of (40.5 ± 9.4)% and dark count rate of (123 ± 34) Hz for 32 individually addressable detectors at minimal noise-equivalent power of (5.1 ± 1.2) · 10−18 W/[Formula: see text]. Our detectors achieve timing jitter as low as 26 ps, which increases to (114 ± 17) ps for high-speed multi-channel operation using dedicated time-correlated single photon counting electronics. Our multi-channel single photon receiver offers exciting measurement capabilities for future quantum communication, remote sensing, and imaging applications.

Integration of photonic integrated circuit functionalities with superconducting nanowire single photon detectors

“…Combining efficient fiber-chip interconnects, low loss waveguides and precise directional couplers with waveguideintegrated SNSPDs in large numbers [3] on a chip it is then possible to configure application specific quantum integrated circuits. We demonstrate such implementations for quantum key distribution receivers designed for time-bin encoding that reach more than 10 Mbit/s secret key rate in urban use cases [4].…”

Integrating large numbers of superconducting nanowire single-photon detectors with nanophotonic waveguides

“…If large numbers of such SNSPDs are required, fabrication yield and system integration become significant challenges. We satisfy the yield requirements by exploiting the capabilities of modern electron beam lithography and reactive ion etching processes for replicating a compact nanowire device in large numbers on a 3.3 mm × 3.3 mm area [2]. Subsequently we select 64 optimal devices from the total set of 160 SNSPDs based on pre-characterization results and route the corresponding waveguides to 3D optical interconnects to an 8 × 8 optical fiber array, as shown in Figure 1.…”