Study Of Stimulated Raman Scatteringand Four-Wave Mixing In Photonic Crystal Fibers

Compared with step-index fiber,Photonic crystal fiber(PCF) has aroused widespread attention in academic and industry communities because of its flexible structure designing and particular optical property- Endlessly single-mode,vivid dispersion characteristies, enhanced nonlinearity and so on..First of all, the relations between structure parameter and cladding effective index of PCF are investigated by a full vectorial effective index method in this paper,the dispersion property of PCF are investigated combined avector method,getting the relations between dispersion characteristics and structure parameter,zero dispersion property around 1310nm or 1550nm are designed.Secondly, we made use of supercell lattice method and full vectorial effective index method to compute the effective area and nonlinear coefficient. the result of supercell lattice method agree with the result got by the finite element method .Then, the fundamentai principle of wavelength conversion is presented by the coupled wave equations, the relation between PCF's length and four-wave mixing'conveersion efficiency is analyzed.the result show the best length of PCF is reduced to several ten meters , the maximum conversion efficiency and the 3-dB tuning bandwidth get raised highly.Finally, the Raman gain coefficient and Raman effective area are analyzed in order to find the relations between geometrical parameters and Raman properties,and the best value of hole diameter.and discover the best air hole diameter's formula; the coupled wave equations of pump wave and signal wave are investigated , The result of calculation shows that the Raman threshold power are reduced highly and reach 50mw of magnitude.