Long distance Brillouin optical time domain reflectometer (BOTDR) sensing system based on bypass remote optical pumped amplifier, Erbium-doped fiber and backward Raman amplification, is achieved 253km sensing distance with 40m spatial resolution.
Aiming at the current demand for precise fault location and early warning of power OPGW optical cables, a method of OPGW optical cable fault location and early warning based on BOTDR/A technology is proposed. This paper proposes a method for locating the connection pole based on the DBSCAN algorithm. The connection point is located through the Brillouin frequency shift curve, and then the fault is accurately located. The Brillouin frequency shift is linearly affected by temperature and strain, which are linear relationships and cross-sensitive. The isolation of the OPGW cable strain and temperature is achieved by the identification result of the fiber optic splicing point. The abnormal region is positioned and warned by strain measurement. Field picture collections are performed for typical abnormal strain areas, and the positioning and cause of fault warning is confirmed. The OPGW fault positioning and early warning method proposed herein, significantly improves the efficiency of fault processing and improves the operational reliability of OPGW optical cables.
We demonstrate an ultrahigh resolution optical spectrometry based on Brillouin dynamic grating (BDG). Taking advantage of creating a long grating in an optical fiber, an ultra-narrow bandwidth optical filter is realized by operating a BDG in a long single-mode fiber (SMF), and the optical spectrometry is performed by sweeping the center wavelength of the filter through swept-tuned laser. In experiment, a 4-fm (0.5 MHz) spectral resolution is achieved by operating a BDG in a 400-m SMF, and the wavelength coverage can be readily extended to C+L band with a commercial tunable laser.
We demonstrate a high-spatial-resolution fast Brillouin optical time-domain analysis scheme based on frequency agility and differential double-pulse for distributed dynamic measurement. The frequency-agility probe wave is obtained from the second-order sideband of the modulated light by using frequency-agility microwave signal from a wideband arbitrary waveform generator. The differential double-pulse technique is proposed to improve the spatial resolution while keeping the capability of dynamic measurement. In experiment, a spatial resolution of 20 cm is achieved by using a 52/50 ns differential double-pulse, and the distributed vibration measurement is demonstrated over a 50-m Panda fiber with a maximum vibration frequency of up to 50 Hz. With only five averages, the standard deviation of the strain accuracy is of 14με;.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.