Research on Distributed Fiber Optical Strain Testing Technology Based on the Adam Algorithm

Distributed Optical Fiber Sensing Technology, with advantages such as long detection distance, resistance to electromagnetic interference, and easy maintenance, is widely applied in various fields including security monitoring, electrical safety, and aerospace. However, the current Distributed Optical Fiber Sensing Technology faces challenges such as short localization distance, limited range for stress measurement, low accuracy, and time-consuming processes. This study proposes a novel approach for extracting Brillouin frequency shift signals using an adaptive gradient descent algorithm (Adam Algorithm). A Brillouin strain testing system based on heterodyne coherent detection is also constructed. Experimental results show that the distributed strain testing system using the Adam Algorithm can achieve accurate and fast measurement of maximum strain up to 9500 µϵ within a range of 10 kilometers. The average strain measurement deviation is 32.88 µϵ, and the time required for frequency shift extraction is less than 18.5 ms. This method provides a theoretical and experimental basis for the application of BOTDR Distributed Optical Fiber Sensing Technology.