Study Of Broadband Fiber For Transmitting Solitons In Low Power And Dual-core Polarization Beam Splitter

With the improvement of communication technology continuously, all-optical communication system has been developed rapidly. As an important research field of all-optical communication, many scientists pay attention to the soliton communication system due to its unique advantages.In this paper, the broadband bandwidth fiber for soliton transmitting at low pump power is studied, which can reduce the standard of pump power and improve the transmission bandwidth in optical soliton communication system; Additionally, it can also improve transmission rate and quality. The new kind of dual-core photonic crystal fiber polarization beam splitter is beneficial for the development of the high-efficiency, miniaturization and integration of optical devices. It is also helpful for the development of optical soliton communication system and the industrialization of all-optical communications system.In this paper, the major contents are as follows:Firstly, a new kind of photonic crystal fiber is proposed. The dispersion, nonlinearity, the pump power of the optical soliton, and the main affect factors of the soliton transmission are analyzed theoretically by the finite element method. Numerical results demonstrate that there is high nonlinearity and low dispersion in the anomalous dispersion region, the bandwidth of the anomalous dispersion of the photonic crystal fiber is1.45μm. The optical soliton can be transmitted easily at low pump power in this region. When the pump pulse width is300fs,the highest average pump power of the first-order soliton transmission is only0.001695W,and which of the fifth-order soliton transmission is only0.04238W.Secondly, the soliton transmission characteristics of the photonic crystal fiber are simulated based on the split-step fourier method. The influences of the relative interval, the relative amplitude, the relative phase, and higher-order nonlinear effects on the optical soliton transmission are analyzed, which is prepared for practical application of this novel photonic crystal fiber.Thirdly, a kind of polarization in SF6soft glass dual-core photonic crystal fiber has been designed by the coupled-mode theory and the finite element method. The birefringence, coupling length, and extinction ratio are been analyzed. The simulation results show that the polarization splitter has shorter coupling length and higher extinction ratio. A118.68μm-long splitter with an extinction ratio of-153.9dB at the communication wavelength of1.55μm is obtained. The extinction ratio maintains better than-20dB with a bandwidth of89nm.