Single-photon linear polarimeter based on a superconducting nanowire array

TL;DR

This paper presents a superconducting nanowire array-based polarimeter capable of resolving single-photon polarization states, demonstrating effective measurement of Stokes parameters with potential for scalable quantum imaging applications.

Contribution

The work introduces a novel superconducting nanowire array design that functions as a polarization-sensitive single-photon detector, enabling polarization measurement at the single-photon level.

Findings

Achieved polarization extinction ratio of ~10 for each nanowire pixel.

Total detection efficiency of approximately 1% at 1550 nm with dark count rate of 680 cps.

Measured AoP and DoLP with mean errors of about -3 degrees and 0.12, respectively.

Abstract

Superconducting nanowire single-photon detectors (SNSPDs) have attracted remarkable interest for visible and near infrared single-photon detection, owing to their outstanding performance. Conventional SNSPDs are generally used as binary photon-counting detector. Another important characteristic of light, i.e., polarization, has not been resolved using standalone SNSPDs. In this work, we simulated, fabricated, and characterized a linear polarimeter based on a four-pixel NbN superconducting nanowire array, capable of resolving the polarization state of linearly polarized light at the single-photon level. The detector array design is based on a division of focal plane sensor, in which the orientation of each nanowire division (pixel) is offset by 45 degree. Each single nanowire pixel operates as a combination of photon detector and almost linear polarization filter, with an average polarization extinction ratio of approximately 10. The total system detection efficiency with four pixels is approximately 1% at a total dark count rate of 680 cps, when the detector array is free-space coupled and illuminated with 1550 nm photons. The Stokes parameters are extracted from polarization measurements of the four pixels. The mean errors of the measured AoP and DoLP were about -3 degree and 0.12, respectively. Our results indicate that it is possible to develop a scalable polarization polarimeter or imager based on a superconducting nanowire array. This detector array may find promising application in single-photon polarization detection and imaging.