Numerical Simulation Of Spatiotemporal Soliton Based On Multimode Fiber

Spatiotemporal solitons(STSs)are of great significance to the development of nonlinear science.Because of STSs's particle properties and its potential for all-optical modulation,researchers have been seeking with great enthusiasm for a soliton wave that is both spatially and temporally localized since it was proposed.More recently,multimode fiber has been considered theoretically as an environment that could support STSs,which attracts people's interest owing to its important application value in large-capacity optical communication and high-power laser.On the other hand,in the past,the simulation of optical fiber transmission is based on CPU calculation,which has low efficiency and limits the in-depth study of optical fiber system.Therefore,in this paper,based on the model of gradient index multimode fiber,the existence condition and transmission dynamics of STSs in multimode fiber are studied by the efficient numerical simulation.The main work of the paper is as follows:1.In this paper,two numerical methods are used:split-step Fourier method and massively parallel algorithm.At the same time,compared with the traditional CPU running environment,this paper designs the CUDA programming model and based on GPU parallel computing,further improves the efficiency of massive parallel algorithm.2.Based on generalized(3+1)-dimensional nonlinear schrodinger equation((3+1)-D GNLSE),the transmission characteristics of(3+1)-D STSs in multimode fiber are studied by using the split-step Fourier method.Through numerical simulation,the temporal and spatial evolution characteristics of STSs and the interaction between STSs are analyzed under different parameters.These results demonstrate that multimode optical fibers can provide a stable mechanism for STSs.3.Based on the generalized multimode nonlinear schrodinger equation(GMMNLSE),the transmission characteristics of coupled-mode STS in multimode fiber are studied by using the massively parallel algorithm.Through numerical simulation,the mode field distribution,dispersion parameters and coupling tensors of the eight modes in the multi-mode fiber are obtained.Then,the influence of different initial pulse width and energy on the transmission characteristics of the eight modes under nonlinear action is studied.Finally,the simulation results are compared with the experimental results to further verify the reliability of the simulation results.