SNR improvement in computed tomography-based distributed Brillouin sensing: a theoretical and numerical study

Distributed fiber sensors based on Brillouin scattering enable long-distance, high-spatial-resolution structural health monitoring. The key challenge lies in improving the inherent inefficiency that arises from the difficulty of achieving position-resolved measurement of the Brillouin gain spectrum, which is fundamentally limited by the one-dimensional nature of optical fibers. Recently, a promising approach based on tomographic reconstruction rather than point-by-point sensing using computed tomography (CT) has been experimentally demonstrated. However, key performance characteristics such as SNR improvement and spatial resolution have not yet been clarified. In this study, we performed a theoretical analysis of distributed Brillouin sensing using the CT method through numerical simulations. Our results revealed that, with only a fewfold degradation in spatial resolution, the CT method can achieve an SNR improvement of approximately N with respect to the number of position-resolving points N, compared to the conventional technique. These highlight the potential of computational imaging techniques to enable new directions in fiber-optic sensing.