Details

Autor(en) / Beteiligte

• Li, Shupeng
• Qing, Ting
• Fu, Jianbin
• Wang, Xiangchuan
• Pan, Shilong

Titel

High-Accuracy and Fast Measurement of Optical Transfer Delay

Ist Teil von

• IEEE transactions on instrumentation and measurement, 2021, Vol.70, p.1-4

Ort / Verlag

New York: IEEE

Erscheinungsjahr

2021

Quelle

IEEE Electronic Library Online

Beschreibungen/Notizen

• Measurement of optical transfer delay (OTD) is crucial to applications such as fiber-distributed multiantenna systems, fiber-optic sensors, and high-capacity optical fiber communications. However, present OTD measurement techniques are inadequate for the demands of high accuracy, high speed, and large measurement range, simultaneously. Here, we propose a novel method based on nonlinear frequency sweeping and phase derived ranging to achieve all the above-mentioned performance. A continuous-wave light modulated by a microwave signal propagates in a device under test. Then, the OTD is mapped into the phase variation of the microwave signal by photodetection. A microwave phase discriminator is used to extract the phase variation from the microwave signal, while the nonlinear frequency sweeping and a novel phase unwrapping algorithm are proposed to resolve 2π phase ambiguity caused by phase detection. Frequencies of the microwave swept signals are set at four selected points in a range of 10 MHz, which ensures high speed and large measurement range. Our experiment results verify an accuracy of ±0.05 ps in measuring an ultrahigh-accuracy optical delay line. In addition, long fiber is also tested, which proves that a measurement range of at least 37 km (theoretically 100 km) can be achieved. Moreover, the measurement speed reaches milliseconds per measurement.