Study On Novel Wavelength Convertor Based On Photonic Crystal Fiber

Wavelength conversion is one of the key technologies in all-optical network. The main purpose of wavelength conversion is solve the competition of wavelength in modern optical network, reduce the blocking probability of the network and reuses the wavelength, so that the capacity of all-optical communication network greatly increased. With the unique optical properties, photonic crystal fiber (PCF) has provided a novel kind of optical transmitted medium. Four-wave mixing wavelength conversion based on dispersion flat PCF has very widely application prospect in fiber communication.The detailed works are listed as follows:Firstly, we have deduced the intrinsic equation derived from Maxwell's, and described the basic idea of PCF analyzed by finite element method (FEM). Further the basic process of PCF's numerical simulation achieved by Femlab has been introduced in detail.Secondly, the mode distributions of PCFs with asymmetric circular-holes and elliptical air-holes have been researched by FEM. We have calculated and analyzed the birefringence resulted from perturbation, and given the relationship between perturbation and birefringence of fiber structure parameters. The results after the numerical simulation are expected to provide references and guiding significance for the design and manufacture of PCF. In addition, the mode distributions and propagation constant of air-hole gradient PCF have been analyzed by using FEM, and the dispersion flat and high nonlinearity of PCF have been calculated.Lastly, the phase match condition of four-wave mixing in PCF has been discussed theoretically. On this foundation, the simulation system of wavelength conversion is built, and the bandwidth of wavelength conversion upto 50nm has been achieved, and the messured maximum FWM-to-signal ratio is -9.16dB. In addition, we have discussed the varision of conversion efficiency versus pump power, the output power of EDFA and the length of PCF, which have guiding significance for the design of experimental structure. The results show that: the varision of pump power has little effect on efficiency of wavelength conversion, and it is a good way that we can improve the efficiency by increase the EDFA power or the length of PCF.