Joint multi-parameter optical performance monitoring method and device suitable for mode division multiplexing system

The invention provides a joint multi-parameter optical performance monitoring method and device suitable for a mode division multiplexing system, and the method comprises the steps: receiving the signal intensity of each path of spatial mode through employing a direct detection technology and only employing a photoelectric detector at a certain intermediate node in the mode division multiplexing system, and converting the signal intensity into an electric signal; carrying out asynchronous sampling on the electric signal by using a sampler; according to the method, asynchronous single-channel sampling images with different parameters are generated, down-sampling is carried out, obtained feature images are sent to a multitask-based residual neural network, and multi-parameter optical performance monitoring is realized at the same time. For each spatial mode in the mode division multiplexing system, only one photoelectric detector and one sampler are needed, optical performance monitoring combining multiple para