Pump encoding in distributed Brillouin fiber sensors

Abstract

Pump encoding is an effective approach to enhance the weak signal detection in distributed Brillouin fiber sensors. In this paper, a new encoding matrix that can improve the detection performance is proposed. Furthermore, a distributed fiber sensor for both single and encoding pump operations is numerically analyzed by using Brillouin-scattering coupled amplitudes equations. The results demonstrate that the matrix can reduce the transmission times for pumping light and simplify the coding process. The power of the scattering signal and the coding gain can be improved with the increasing code length. The detected scattering optical power is almost three orders of magnitude higher than that of the single pulse pump, as the coding length is 31, corresponding to 14.4 % improvement for the coding gain compared with the S matrix encoding method. At the same time, the temperature uncertainty can also be decreased.