Author(s): Li, X (Li, Xiao); Ren, MZ (Ren, Meizhen); Zhang, JS (Zhang, Jiashun); Wang, LL (Wang, Liangliang); Chen, W (Chen, Wei); Wang, Y (Wang, Yue); Yin, XJ (Yin, Xiaojie); Wu, YD (Wu, Yuanda); An, JM (An, Junming)

Source: PHOTONICS RESEARCH Volume: 9 Issue: 2 Pages: 222-228 DOI: 10.1364/PRJ.406123 Published: FEB 2021

Abstract: Quantum key distribution (QKD) provides a solution for communication of unconditional security. However, the quantum channel disturbance in the field severely increases the quantum bit-error rate, degrading the performance of a QKD system. Here we present a setup comprising silica planar light wave circuits (PLCs), which is robust against the channel polarization disturbance. Our PLCs are based on the asymmetric Mach-Zehnder interferometer (AMZI), integrated with a tunable power splitter and thermo-optic phase modulators. The polarization characteristics of the AMZI PLC are investigated by a novel pulse self-interfering method to determine the operation temperature of implementing polarization insensitivity. Over a 20 km fiber channel with 30 Hz polarization scrambling, our time-bin phase-encoding QKD setup is characterized with an interference fringe visibility of 98.72%. The extinction ratio for the phase states is kept between 18 and 21 dB for 6 h without active phase correction. (C) 2021 Chinese Laser Press

Accession Number: WOS:000614927100019

ISSN: 2327-9125

Full Text: https://www.osapublishing.org/prj/fulltext.cfm?uri=prj-9-2-222&id=446942