Analysis of sensing characteristics of chaotic Brillouin dynamic grating

The distributed fiber-optic sensing technology based on chaotic Brillouin dynamic grating (BDG) presents distinct advantages, notably high spatial resolution and the ability to decouple temperature and strain measurements. A comprehensive understanding of the sensing characteristics is imperative for advancing its performance capabilities. In this paper, we analyze the gain and reflection characteristics as a function of the grating length, which is adjusted by controlling the chaotic optical spectrum. The influence of varied lengths of chaotic BDGs on critical sensing parameters-namely, temperature coefficient, strain coefficient, and spatial resolution-is systematically researched. The results elucidate that the parameters such as gain spectrum, reflection spectrum, and spatial resolution can be flexibly adjusted according to the grating length, while the temperature coefficient and strain coefficient, which play an important role in practical sensing applications, do not depend on the grating length.