High-resolution recognition of FOAM modes via an improved EfficientNet V2 based convolutional neural network

Vortex beam with fractional orbital angular momentum (FOAM) is the excellent candidate for improving the capacity of free-space optical (FSO) communication system due to its infinite modes. Therefore, the recognition of FOAM modes with higher resolution is always of great concern. In this work, through an improved EfficientNetV2 based convolutional neural network (CNN), we experimentally achieve the implementation of the recognition of FOAM modes with a resolution as high as 0.001. To the best of our knowledge, it is the first time this high resolution has been achieved. Under the strong atmospheric turbulence (AT) (C_n^2 = 10^ - 15 m^ - 2/3) , the recognition accuracy of FOAM modes at 0.1 and 0.01 resolution with our model is up to 99.12