Optical time delay measurement method and device based on optical vector analysis

Abstract

The invention discloses an optical time delay measurement method based on optical vector analysis. The method comprises the following steps: carrying out intensity modulation on a single-frequency optical carrier of which the frequency periodically changes along with time by using a microwave frequency sweeping signal; inputting a generated modulation optical signal into an optical link to be measured, and converting the reflected modulation optical signal into an electric signal; and extracting amplitude-phase information of the electric signal, and carrying out inverse Fourier transform on the amplitude-phase information to obtain a time-domain pulse response of the optical link to be measured, and calculating the optical time delay of each reflection point according to the time-domain pulse response of each reflection point included in the time-domain pulse response. The invention further discloses an optical time delay measurement device based on optical vector analysis. Compared with the prior art, the method and device have the advantages of ultra-long measurement distance, high time domain resolution and high time delay measurement precision at the same time.

Description

technical field [0001] The invention relates to the technical field of optical measurement, in particular to an optical delay measurement method. Background technique [0002] With the rapid development of optical information systems, high-precision optical delay measurement and control has become the key to the development and application of high-performance information systems such as 5G wireless communication networks, optically controlled phased arrays, and distributed radar networks. During the development and production of optical devices, single-ended detection is required to improve production efficiency. However, for an optical link, it is generally composed of a variety of devices, involving the coupling of optical fibers and other materials, which will generate multiple reflection points, and the reflected light at each reflection point interferes with each other, causing serious damage to the delay measurement of the optical link. influences. This type of probl...

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Problems solved by technology

The measurement accuracy of the pulse method is limited by the pulse width, generally on the order of nanoseconds, which cannot meet the requirements of high-precision time delay measurement, and its measurement accuracy and measurement distance are a pair of contradictory quantities; the frequency scanning interferometry can achieve higher measurement Accuracy, but its essence is to exchange high measurement accuracy through large frequency domain bandwidth, which cannot measure narrowband optical devices and long optical fiber links, and its application is limited in many scenarios; the phase extrapolation method uses the phase change during transmission to solve the optical fiber delay, which can Realize the measurement accuracy of tens of femtoseconds in the narrow-band measurement range of several GHz (S.P.Li, T.Qing, J.B.Fu, X.C.Wang, S.L.Pan, "High-Accuracy and FastMeasurement of Optical Transfer Delay," IEEE Transactions on Instrumentation and Measurement, vol.70, 8000204, 2021.), but it cannot measure multi-path transmission delay, and cannot have time-domain resolution while ensuring measurement distance and measurement accuracy, so it cannot be applied to the diagnosis of optical fiber links

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