Open AccessMichelson interferometer based phase demodulation for stable time transfer over 1556 km fiber links
Author(s) -
Jintong Lin,
Zhaohui Wang,
Zitong Lei,
Jiameng Dong,
Youlin Wang,
Jianming Shang,
Tianwei Jiang,
Bin Luo,
Song Yu
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.420712
Subject(s) - demodulation , optics , michelson interferometer , interferometry , signal (programming language) , physics , phase modulation , modulation (music) , phase (matter) , optical fiber , time transfer , phase noise , telecommunications , computer science , channel (broadcasting) , acoustics , quantum mechanics , programming language , satellite , astronomy
Time transfer based on phase modulation schemes has attracted extensive attention in recent years. We propose and experimentally demonstrate an adjustable and stable Michelson interferometer (MI) with a DC phase tracking algorithm for two-way time transfer. Time signal with one pulse per second (1 PPS) is loaded on an optical carrier modulated in phase and demodulated by a Michelson interferometer. The whole compact and cost-effective demodulator is symmetrical with a single coupler to split and recombine optical waves, flexible with one photodetector and a bias tee to separate the DC signal and recovery pulses and stable with a phase modulator to compensate for the drift-phase noise. We show the implementation of modulation and demodulation of the time signal and obtain the stability of 2.31 × 10 -11 at 1000 s averaging time. We then demonstrate two-way time transfer over 1556 km lab fibers. The experimental result shows time interval stability of 1 PPS with 5.62 × 10 -11 at 1000 s averaging time. It has the potential to transfer time signals in long-distance fiber optic links.