Orbital angular momentum optical communications enhanced by artificial intelligence

Abstract

Angular momentum of light can be divided into spin angular momentum (SAM) and orbital angular momentum (OAM). Due to the theoretically unlimited orthogonal states, the physical dimension of OAM provides a potential solution to boost the information capacity. The OAM multiplexing and modulation techniques have been implemented to meet the continuous growth of bandwidth requirements, resulting in the concept of OAM optical communication. However, the performances of the traditional optical OAM detection techniques degrade seriously in the practical application of OAM optical communications. Thanks to the powerful data analysis advantages, the cutting-edge machine learning (ML) algorithms have been widely used in the field of image processing, laying the technical foundation for OAM recognition. This paper reviews the recent advances on OAM optical communications that are enhanced by ML methods. More than the traditional OAM detection methods, the OAM demodulation methods based on multiple network architectures, including the support vector machine (SVM), self-organizing map (SOM), feed-forward neural network (FNN), convolutional neural network (CNN), and diffractive deep optical neural network (D2NN), have been summarized. We also discuss the development of the spiking neural network and on-chip D2NN, opening a possible way to facilitate the future ultra-low power and ultra-fast OAM demodulation technology.

Ultra-Degree-of-Freedom Structured Light for Ultracapacity Information Carriers

“…Indeed, such notion has driven intense research efforts and empowered many novel applications as well. Together with structured light with multiple DoFs, great potentials are unraveled and will continue to motivate new applications . It is expected that further expansion of the modulation DoFs of light and the DL method will motivate the fundamental and applied studies for next-generation information technology.…”

Machine learning meets singular optics: speckle-based structured light demultiplexing

“…The accuracy of detection using these traditional methods is limited by alignment issues, noise, and beam wandering. Almost a decade ago, artificial intelligencebased structured light recognition models were proposed and used in optical communication links 4,5 . These models uplifted the constraints of traditional detection methods by reducing the complexity, boosting the speed of detection, and automating the process.…”

Ellipse‐Like Orbital Angular Momentum Multiplexed Holography and Efficient Decryption Utilizing a Composite Ellipse‐Like Lens

“…The spatial frequencies of a carefully designed amplitude distribution and a beam-steering grating serve as the decoding key for extracting information from each OAM channel in OAM multiplexing holography. [46][47][48] However, the study of fast decryption techniques based on OAM multiplexed holography is relatively limited, and further research and development are required to explore efficient decryption methods that can complement the encoding process and improve overall system performance. In the era of big data, the storage and security of vast amounts of data have become critical research areas essential to societal progress.…”