Author(s): Li, X (Li, Xiao); Wang, LL (Wang, Liang-Liang); Zhang, JS (Zhang, Jia-shun); Chen, W (Chen, Wei); Wang, Y (Wang, Yue); Wu, D (Wu, Dan); An, JM (An, Jun-Ming)

Source: CHINESE PHYSICS B Volume: 31 Issue: 6 Article Number: 064212 DOI: 10.1088/1674-1056/ac40fe Published: JUN 1 2022

Abstract: A quantum key distribution transmitter chip based on hybrid-integration of silica planar light-wave circuit (PLC) and lithium niobates (LN) modulator PLC is presented. The silica part consists of a tunable directional coupler and 400-ps delay line, and the LN part is made up of a Y-branch, with electro-optic modulators on both arms. The two parts are facet-coupled to form an asymmetric Mach-Zehnder interferometer. We successfully encode and decode four BB84 states at 156.25-MHz repetition rate. Fast phase-encoding of 0 or pi is achieved, with interference fringe visibilities 78.53% and 82.68% for states |+ and |-, respectively. With the aid of an extra off-chip LN intensity modulator, two time-bin states are prepared and the extinction ratios are 18.65 dB and 15.46 dB for states |0 and |1, respectively.

Accession Number: WOS:000807765100001

ISSN: 1674-1056

eISSN: 2058-3834

Full Text: https://iopscience.iop.org/article/10.1088/1674-1056/ac40fe