Full-Stokes polarimetric measurements and imaging using a fractal superconducting nanowire single-photon detector

Abstract

Measuring the states of polarization (SoP) of light is fundamentally important for applications ranging from communication, sensing, spectroscopy, imaging, to navigation. Superconducting nanowire single-photon detectors (SNSPDs) are ideal detectors of choice for faint-light detection and measurements, but SNSPDs themselves cannot resolve the SoP of photons. Here, based on a fractal SNSPD, we demonstrate a full-Stokes polarimetric measurement system that can measure arbitrary SoP of faint light. The measured SoPs are in excellent agreement with those of a state-of-the-art commercial polarimeter, but the sensitivity of our system reaches <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mo>−</mml:mo> </mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>86.6</mml:mn> </mml:mrow> <mml:mspace width="thickmathspace"/> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">d</mml:mi> <mml:mi mathvariant="normal">B</mml:mi> <mml:mi mathvariant="normal">m</mml:mi> </mml:mrow> </mml:mrow> </mml:math> , which is 26.6 dB better than that of the commercial counterpart. As a direct application, we further demonstrate remote polarimetric imaging (i.e., polarimetric LiDAR) with a complete set of polarimetric contrast.