A novel optical performance monitoring(OPM) method based on asynchronous optical-sampling,eye diagram reconstruction and artificial neural network(ANN) is presented.Firstly,the monitored optical signal is optically sampled in asynchronous way,and the eye diagrams are reconstructed by software-synchronized algorithm.Secondly,the features of reconstructed eye diagrams are extracted to train the artificial neural network.Finally,the outputs of the trained neural network are used to monitor optical ..