Impulse Response Characterization of a Commercial Multimode Fiber using Superconducting Nanowire Single-Photon Detectors

Abstract

Time-of-flight measurements are key to study distributed mode coupling and differential mode group delay (DMDG) in multimode fibers (MMFs). However, current approaches using regular photodetectors with limited sensitivity preclude the detection of weak modal interactions in such fibers masking interesting physical effects. Here we demonstrate the use of high-sensitivity superconducting nanowire single-photon detectors (SNSPDs) to measure the mode transfer matrix of a commercial graded-index multimode fiber. Two high performance 45-mode multi-plane light conversion (MPLC) devices served as the mode multiplexer/demultiplexer. Distributed mode coupling and DMDG among different mode groups are accurately quantified from the impulse response measurement. We also observed cladding modes of the MMF as a pedestal of the pulse in the measurement. This work paves way for applications such as quantum communications using many spatial modes of the fiber.

arXiv comment10 pages, journal paper

References in corpus (7)

• Quantum computational advantage using photons
• Quantum key distribution over 40 dB channel loss using superconducting single photon detectors
• Demonstrating sub-3 ps temporal resolution in a superconducting nanowire single-photon detector
• Phase-Programmable Gaussian Boson Sampling Using Stimulated Squeezed Light
• Reconfigurable quantum photonics with on-chip detectors
• Ultimate low system dark count rate for superconducting nanowire single-photon detector
• Quantum key establishment via a multimode fiber