Abstract
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) \((C_n^2 = {10^{ - 15}}\,{{\rm{m}}^{ - 2/3}})\), the recognition accuracy of FOAM modes at 0.1 and 0.01 resolution with our model is up to 99.12% and 92.24% for a long transmission distance of 2000 m. Even for the resolution at 0.001, the recognition accuracy can still remain at 78.77%. This work provides an effective method for the recognition of FOAM modes, which may largely improve the channel capacity of the free-space optical communication.
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Acknowledgements
This work was supported by the National Natural Science Foundation of China (Grant Nos. 62271332, 12374273, and 62275162), the Guangdong Basic and Applied Basic Research Foundation (No. 2023A1515030152), the Shenzhen Government’s Plan of Science and Technology (Nos. JCYJ20180305124927623 and JCYJ20190808150205481), and the Training Program for Excellent Young innovators of Changsha (No. kq2107013).
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Shi, Y., Ma, Z., Chen, H. et al. High-resolution recognition of FOAM modes via an improved EfficientNet V2 based convolutional neural network. Front. Phys. 19, 32205 (2024). https://doi.org/10.1007/s11467-023-1373-4
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DOI: https://doi.org/10.1007/s11467-023-1373-4