tailieunhanh - Báo cáo khoa học: "Ảnh hưởng của tán sắc bậc ba lên soliton lan truyền trong sợi quang."

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. .