Electromagnetic Metasurface Design For Mode Multiplexing In Fiber

With the explosive growth of the amount of information,how to increase the transmission capacity of information has become a scientific problem to be solved urgently.Optical fiber communication is one of the important means to realize high-speed information transmission.The data transmission rate of the existing single-mode fiber has reached the limit.If we can achieve the mode multiplexing in fiber,and make different modes to carry different information,the channel capacity can be effectively improved.How to achieve the excitation of higher-order modes in multimode fibers has become a bottleneck restricting the use of multimode fibers.As an emerging electromagnetic material,metasurface has the advantages of lightness,thinness,easy processing,etc.,and can effectively control the physical characteristics of electromagnetic waves such as phase and amplitude,so it can be used to excite higher-order modes in fibers.After summarizing the shortcomings of the existing implementation of mode multiplexing,a kind of metasurface structure is designed to achieve the mode multiplexing in fiber.The main research work and research results are introduced as follows:First,the importance of mode multiplexing in fiber for improving channel capacity in optical communications is introduced.The shortcomings of the existing plan for mode multiplexing are analyzed.Second,in view of the shortcomings of the existing plan for mode multiplexing,a solution to achieve mode multiplexing in fiber using metasurface is proposed,and the feasibility and advantages of the solution are demonstrated.Thirdly,the feasibility of two kind of metasurface is analyzed separately,and one of them is determined to be usedFourth,in response to the problem of inverse design for metasurface nanostructure,a deep learning GAN(Generative Adversarial Network)is trained.after the network converges,a metasurface nanostructure that meets the requirements is designed.Finally,the simulation in CST of the fiber and the designed metasurface structure was carried out,and the mode multiplexing in fiber is successfully realized.