Tuyển tập những báo cáo nghiên cứu khoa học hay nhất của trường đại học vinh tác giả: 7. Đinh Xuân Khoa, Bùi Đinh Thuận, Ảnh hưởng của tán sắc bậc ba lên soliton lan truyền trong sợi quang. | ĐẠI HỌC VINH TẠP CHÍ KHQA HỌC TẬP XXXVI số 2A-2007 INFLUENCE OF THIRD-ORDER DISPERSION ON SOLITON S TRANSMISSION IN OPTICAL FIBERS DINH XUAN KHQA a BUI DINH THUAN a Abstract. In this article we use split-step Fourrier method to investigate the influence of loss and third-order dispersion on a transmission soliton in optical fibers. 1. Introduction Soliton in optical fibers is formed by the balance between phase selfmodulation and dispersion caused by group velocity. The low-loss transmission of soliton in optical fibers is described by non-linear Schrodinger equation. The loss and dispersion are main factors which diminish transmission distance and durable of soliton. Normally we consider only second-order dispersion factor. However when pulse s width is small higher-order dispersion factors are not negligible. Besides in optical fibers material dispersion equals zero at the wavelength of 1300 nm. In this case the change of pulse s form and its durable depend on high-order dispersion. In order to investigate transmission of soliton in optical fibers we can use back-scattering and perturbation methods. But if the loss is considered back-scattering method does not give correct solution. In this article we use Split-Step Fourrier algorithm to investigate the transmission of light pulse in non-linear dispersion media thenceforth investigate the influence of high-order dispersion on soliton s transmission. 2. Transmission equation Pulse s transmission in optical fiber is described by equation 1 3 dA dz a R 3A i d2 A A dA 2 A dt 2 dt2 6 dt3 lAI2A w2A -TRA d 0 0 dt dt diAl2 _ u 1 where A A z t is a complex envelop function of optical field. This function varies slowly with time and z position along optical fiber a is loss factor of optical fiber P1 j2 and j3 are first second and third-order dispersion factors respectively Y is nonlinear factor of optical fiber y ffl0 term describes self-steeping effect yTr term describes Raman scattering effect. Nhận bài ngày 19 9 2006. .
