Search

The coupled-mode equation for the magneto-optic four-wave mixing existing in a fiber with magneto-optic and nonlinear effects as perturbation is derived.The parametric processes of the isotropic magneto-optical nonlinear fiber are analytically investigated,and the phase matching condition can be achieved by the dispersion characteristics for the magneto-optic coupling coefficient.In the case that the wavelength dependency of fiber Verdet constant is negligible,the magnetic control characteristics of fiber parametric gain are analyzed for the incident left-hand circular polarization.The necessity of using magneto-optic and nonlinear fiber with high Verdet constant in the experiments is pointed out.The results show that,1) for the magneto-optical nonlinear fiber with low birefringence,the maximal parametric gain can be obtained by optimizing the magnitude of fiber birefringence;2) from the monotonic dependence of parametric gain on the magneto-optic coupling coefficient,the magnetic adjustability of parametric gain can be improved by appropriately choosing fiber length,pump power and polarization states of guided optical waves.

According to the linearized three-section model of input/output power transfer function(TF),the theoretical assessment method of all-optical reshapers' performance is investigated and verified by simulation of four-wave-mixing-based scheme.The performance of all-optical reshapers dependent on the input signal of Gaussian distribution is analyzed.The transfer function is divided into five regions from low to high power levels,and a larger improvement of quality factor or BER performance can be obtained for the cases that the average level of mark pulses exists in the fifth region.With the increase of the TF′s second-section slope for a desirable reshaper,the gain saturation of quality factor or BER performance will occur and the extinction ratio will be improved linearly.

The reflection spectra of polarization-mode conversed light in Magnetooptic Fiber Bragg Gratings(MFBGs) dependent on the magnetooptical coupling intensity is investigated.According to the magnetooptic coupled-mode theory combined with the propagation property of fiber Bragg grating,the magnetic control characteristics of the MFBGs are analyzed numerically.The 3 dB bandwidth tunable filter is obtained by adjusting the magnetooptical coupling intensity.The clock extraction of 40 Gbps RZ data signal by utilizing the comb filtering of MFBGs under bias magnetic fields is simulated and the jitter performance of the MFBGs is also analyzed.