Analysis And Simulation Of The Distributed Optical Fiber Sensing Signal Based On Brillouin Scattering

Distributed fiber optical sensing technology is a new sensor technology, it has anti-electromagnetic interference, anti-corrosion, continuous monitoring, etc., and has great value in the actual industrial measurement and monitoring. Based on brillouin scattering, optical fiber sensing technology can simultaneously monitor the temperature and strain, and is the point on a continuous space, but it has a certain resolution and measurement accuracy. In this paper, the fiber optic sensing principles and technology based on stimulated Brillouin scattering effect are researched, which is divided into the following areas:Firstly,through the transient equation and MATLAB numerical calculation, the variation of pumping light and scattered light is researched in the transient sensing system.It is show that stokes light in sensing system produces stimulated brillouin amplification effect.The power variation characteristics of light scattering is calculated, so it show that double light source system by the medium effect of internal noise is smaller than the single source system. Secondly,in the system,the frequency domain and time domain characteristics of the scattered light are analyzed.The relationship between the pulse width and the Brillouin scattering spectrum waveform changes,and shows the pulse width increases,the spectral waveform changes,which is helpful for the sensing accuracy control; The time-domain of the characteristics of the scattered light is analyzed and it is seemed that the scattering light having a pulse characteristics under generated pulse light, and is found that the scattered light has the ability to provide the positioning of the OTDR based on the brillouin scattering,which is help for improving sensing system. Finally, BOTDA system performance is analyzed and simulated by Optisystem and MATLAB. The results show that the change of the DC probe, the incident light frequency offset and multi pulse will affect the signal to noise ratio, and then the incident pump power pulse width changes not only affect the scattering of light, but affect the scattering light spectrum width, which is helpful for the simulation optimization of sensing signal spectrum width, signal power and signal to noise ratio.