Shanghai Microsystems Institute and others have developed a mobile high-efficiency superconducting single photon detection system

Recently, Li Hao and You Lixing from the Shanghai Institute of Microsystems of the Chinese Academy of Sciences have developed a mobile superconducting single photon detection system based on a small liquid helium dewar (operating temperature 4.2K) with a system detection efficiency of more than 70% at 1550nm, paving the way for future high-performance single photon detection applications based on mobile platforms (airborne, vehicle mounted, etc.).

The relevant research results are titled "Mobile Superconducting Strip Photon Detection System with Efficiency Over 70% at a 1550 nm Wavelength" and published in Optics Express.

Superconducting strip photon detector (SSPD), as a high-performance single photon detector, is widely used in fields such as quantum information and weak light detection, promoting technological progress in related fields. However, the comprehensive detection performance of SSPD depends on the operating temperature of the device (the lower the temperature, the higher the detection efficiency of the system).

So far, efficient SSPD systems typically require the use of GM refrigerators (T ≤ 2.5 K), adsorption refrigerators (T ≤ 0.85 K), or even lower temperature refrigerators. The quality, volume, and power consumption of these systems have become key factors limiting the application of SSPD in mobile platforms such as airborne platforms. If high-efficiency SSPD can be achieved at a working temperature of 4.2K, a small, low-power, and short-term superconducting single photon detection system can be constructed using a small liquid helium dewar, providing feasible solutions for mobile platform applications such as drones and aviation.

The optical response performance of SSPD is closely related to the disorder of superconducting thin film materials. One of the methods to improve the working temperature of SSPD is to use highly disordered superconducting thin film material regulation technology to achieve superconducting thin film materials with higher surface resistance and enhance the detection sensitivity of SSPD. This study achieved SSPD with near saturation detection efficiency at 4.2K operating temperature using NbTiN superconducting thin film material with a surface resistance exceeding 600 Ω. At the same time, this work developed and manufactured a small liquid helium dewar dedicated to SSPD, combined with a low-power battery based circuit module, to achieve a mobile single photon detection system with a detection efficiency of over 70%.

The research work has received support from the National Natural Science Foundation of China and the Shanghai "Sailing Plan".

Paper link:

https://doi.org/10.1364/OE.501552

(Left) System diagram of liquid helium dewar; (Right) Detection efficiency and dark counting performance curve of mobile SSPD system

Source: Shanghai Institute of Microsystems and Information Technology