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International Conference on Optical Communications and Networks (ICOCN)

Two-way Optical Phase Comparison at 10-21 Level over 200-km fiber link

Zang Qi, Xue Deng, Jiao Dongdong, Jie Liu, Xiang Zhang, Jing Gao, Dan Wang, Dong Ruifang, Tao Liu, Shougang Zhang

Published Aug 1, 2019• 1 citation
Publisher

Abstract

This works demonstrates an improved local two-way optical phase comparison method. Based on this scheme, we implement a real-time frequency comparison over a bi-directional 200-km fiber spool link with a Bi-EDFA. The achieved relative frequency stability is 9.7E-18 at 1 s integration time and reaches 1.4E-21 at 10,000 s.
DOI
10.1109/icocn.2019.8934273

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We performed a two-way remote optical phase comparison on optical fiber. Two optical frequency signals were launched in opposite directions in an optical fiber and their phases were simultaneously measured at the other end. In this technique, the fiber noise was passively cancelled, and we compared two optical frequencies at the ultimate 10-21 stability level. The experiment was performed on a 47 km fiber that is part of the metropolitan network for Internet traffic. The technique relies on the synchronous measurement of the optical phases at the two ends of the link, that is made possible by the use of digital electronics. This scheme offers some advantages with respect to active noise cancellation schemes, as the light travels only once in the fiber
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We performed a two-way remote optical phase comparison on optical fiber. Two optical frequency signals were launched in opposite directions in an optical fiber and their phases were simultaneously measured at the other end. In this technique, the fiber noise is passively canceled, and we compared two optical frequencies at the ultimate 10(-21) stability level. The experiment was performed on a 47 km fiber that is part of the metropolitan network for Internet traffic. The technique relies on the synchronous measurement of the optical phases at the two ends of the link, which is here performed by digital electronics. This scheme offers some advantages with respect to active noise cancellation schemes, as the light travels only once in the fiber.