oa Integrated Distributed Acoustic Sensing Interrogator Based on Silicon Photonics

Distributed acoustic sensing (DAS) is an important branch of fiber optic sensing, but there have been problems of size, weight, and cost that hinder its practical application. In order to solve these problems, photonic integration technology is an effective means. In this work, we have demonstrated a highly integrated DAS interrogator based on the silicon-on-insulator (SOI) platform. The DAS interrogator contains two parts, a transmitter based on a Mach-Zehnder modulator and a coherent receiver. In the demo experiment, with time-gated digital optical frequency domain reflectometry (TGD-OFDR) chosen as the testing DAS scheme, the strain resolution is about 77.0 pε/√Hz with the spatial resolution of 0.819 m along the total 12.2 km sensing fiber, which is comparable to the discrete system. To the best of our knowledge, this is the first integrated DAS interrogator, and achieves a high level of integration and excellent performance. The implementation of the integrated DAS system also demonstrates the integration possibilities of fiber optic sensing systems of other architectures, and that these integrated systems may achieve good performance. The integrated DAS heralds the possibility of making the application scenarios of DAS expand. With the development of silicon photonics technology, devices that are not integrated at this stage, such as lasers, can also be integrated, truly realizing the full integration of the system.