Design And Implementation Of Magnetically-Controllable Optical Fiber Interference Device

Magneto-optic effect leads to the rotation of the polarization plane of the guided wave, the combination of the magneto-optic effect and the four-wave mixing which relies on the polarization of the wave guide can realize magnetically-controllable non-linear information processing. In this article, we take MATLAB numerical calaulation and Optisystem simulation together to study the characteristics of the multi-stable transfer function of the guided wave and its application in multilevel regeneration in the highly-nonlinear fiber and fiber Bragg grating. Analyze the effects that the applied magnetic field has on them.The main work and innovations are as follows:1. Starting from the coupled-mode theory of the polarized wave, we derivate the non-linear evolution equations of the circularly polarized guided wave in the magnetically-circular birefringence fiber. Calculating the power transfer curve of the pump, signal and idler in the magneto-optical fiber with the method of runge-kutta under the condition of with or without the applied magnetic field. The consistency of the calculation results with the literature indicates the validity of the theoretical derivation. We get the results that the all optical Mach-Zenhder interferometer(MZI), which is made from the magneto-optical fiber, has the switching effect under the self-phase modulation and the switch threshold can be cut down by applying the magnetic field. The MZI construction can realize more function of optical information processing than the nonlinear optical loop mirror(NOLM).2. In order to get the multi-stable transfer curve of the guided wave, we proposed a scheme based on the nearly parallel mach-zehnder interference model, and the specific implementation process can be analyzed by the iterative method. Taking the double nested MZI model as example, we calculate the multi-stable power transfer curve of the right-circularly polarized continuous pump wave with MATLAB and explore the jitter suppression performance of the 4PAM signal; discuss the switching effect on the other output port and the effect that the applied magnetic field has on the multilevel reshaping performance. Dynamically simulating the multi-stable transfer function of the double nested MZI model with Optisystem, describing the jitter suppression performance of the 4PAM signal in this model more intuitively. And the simulation results are consistented with the MATLAB calculation results.3. Starting with the nonlinear coupled-mode equations of the guided optical waves in the magneto-optic fiber Bragg grating (MFBG), the amplitude transfer curve of the transmitted light is numerically calculated for the incident right-circularly polarized wave. It is shown that, the performance of amplitude jitter suppression in the stable states of high level is better than that of low level; the jitter suppression in the multi-stable regions can be enhanced when the magnetic field is applied to the MFBG in the reversely propagating direction of the input wave; and by adjusting the applied magnetic field, the multi-stable levels can be tuned flexibly, which is helpful for developing the intelligent all-optical devices for multilevel regeneration. There is a equivalence relation between the working wavelength of guided wave and the magnetic field when the right-and left-circularly polarized wave are uncoupling.