Font Size: a A A

Research On Distributed Optical Fiber Sensor Based On Brillouin Scattering

Posted on:2018-05-22Degree:MasterType:Thesis
Country:ChinaCandidate:Y M TaoFull Text:PDF
GTID:2348330518494615Subject:Electronic Science and Technology
Abstract/Summary:PDF Full Text Request
This Research is based on stimulated Brillouin scattering effects, by which distributed optical fiber temperature and stress sensing system can obtain information of optical signal transmission from temperature or stress change with time and space. Due to excellent characteristics of optical fiber, suitable in harsh environment such as flammable, explosive and strong electromagnetic interference, it is widely used and urgently needed in large-scale construction disaster early warning, long-distance oil and gas pipeline safety monitoring.One of the popular research areas in the field of Brillouin optical fiber sensing is to improve the performance of BOTDA, which includes spatial resolution, frequency accuracy, sensing distance and measuring time. On the one hand, this thesis focuses on the dual-light source distributed BOTDA sensing system. In this system, frequency tracking technologies of the light source are evaluated, and AD9901 is used as the digital frequency discrimination module as well as a digital frequency discrimination extraction experiment system of double light source is established with bandwidth of 100MHz. On the other hand, eliminating the polarization noise is the key point to enhance the performance of BOTDA sensor system. This research has deeply analyzed how far the existing technology can eliminate polarization noise and the generation mechanism of polarization noise. Furthermore, experimental validation of traditional BOTDA system with polarization fading phenomenon and elimination polarization noise with Polarization Switch are completed as estimated. In view of this situation, a new polarization compensation technique is proposed working with the three-frequency probe light and orthogonal pump pulse pair. It verified the polarization compensation effects and temperature sensing performance. Consequently, this research demonstrated long-distance distributed optical fiber sensor based on Brillouin scattering effects, without additional measuring time, either reducing sensing performance with polarization compensation.
Keywords/Search Tags:brillouin scattering, distributed optical fiber sensing, polarization noise, digital frequency discriminator
PDF Full Text Request
Related items