Cavity-Enhanced and Ultrafast Superconducting Single-Photon Detectors

Area of Science:

• Quantum optics
• Nanophotonics
• Superconducting devices

Background:

• High-efficiency, ultrafast single-photon detectors are crucial for quantum photonic circuits.
• Superconducting nanowire detectors offer promise but are limited by speed due to long nanowires.
• Current designs face trade-offs between absorption efficiency and detector speed.

Purpose of the Study:

• To overcome the speed limitations of superconducting nanowire single-photon detectors.
• To enhance detection efficiency and speed for integrated quantum photonic applications.
• To develop detectors compatible with silicon nanophotonic circuits.

Main Methods:

• Fabricated superconducting nanowires perpendicular to optical waveguides, reducing device length to below 1 μm.
• Integrated nanowires into photonic crystal cavities to boost absorption efficiency.
• Embedded cavity-enhanced detectors within silicon nanophotonic circuits.

Main Results:

• Achieved detection efficiency enhancement by over an order of magnitude.
• Demonstrated detectors with sub-nanosecond decay (∼120 ps) and recovery times (∼510 ps).
• Attained low timing jitter (∼32 ps), enabling potential GHz count rates and multiphoton detection.

Conclusions:

• Cavity-enhanced superconducting nanowire detectors offer a viable solution for high-efficiency, ultrafast single-photon detection.
• The demonstrated detectors are suitable for telecom wavelengths and integration into silicon nanophotonic platforms.
• These advancements pave the way for high-performance quantum photonic integrated circuits.