Magneto-optical Light Pulse Propagation In Nonlinear Fiber With Step-by-step Fourier

With development of a variety of highly nonlinear optical fiber, photonic information processing devices based on fiber nonlinear effects are concerned. Magneto-optical nonlinear fibers, as a class of special fibers, possess high magneto-optical effects and nonlinear effects with wide application prospects in magnetic field sensing, optical communication and optical information processing field. The research works are as follows:1. Nonlinear propagation of optical pulses in magneto-optical fibers is described according to the perturbation theory. The magneto-optical effect and nonlinearity are regarded as the perturbation expressed by the additional electrical polarization. And then, the magneto-optical and nonlinear coupled mode equations of optical pulses can be derived from Maxwell's equations.2. According to the characteristics of elliptical birefringence in magneto-optical fiber, we put forward the eigen and non-eigen nonlinear coupled-mode equations for guided optical waves and analyze the accuracy of the modified split-step Fourier method (SSFM). It shows that the eigen nonlinear coupled mode equations are fit for the modified split-step Fourier method.3. For the self-phase modulation (SPM) characteristics, the relationship between the equivalent nonlinear coefficient and the ellipticity of eigen elliptical polarized light is obtained. The maximum of nonlinear phase shift induced by SPM increases with the decrease of applied magnetic field, and then the magnetic control mechanism of nonlinearity is opened out.4. The modified split-step Fourier method (SSFM) is also used to calculate the propagation characteristics of light pulses in the fibers. With the increase of magnetic field, the pulse spectrum can be broadened and the polarization dependency of nonlinearity reduces.