The Investigation On Nonlinear Characteristic Of Birefringent Photonic Crystal Fiber With

Photonic crystal fiber has strong nonlinear effects. Under the action of ultrashort laserpulse, the very good supercontinuum phenomenon could be generated in highly nonlinearPCF. The supercontinuum can be achieved by minishing the area of core, increasing theair filling fraction and changing the dispersion or birefringence characteristics. In thispaper, all kinds of characteristics of PCF have been system analyzed by using finiteelement method. The preparation process of PCF has been investigated. And an improvedpreparation method is proposed. We conducted experimental research using the PCF withhigh nonlinear and birefringent of preparation success. The pulse broadening phenomenain normal dispersion is analyzed.Firstly, a kind of double arrow PCF with high nonlinear and birefringent wasdesigned utilizing FEM. The characteristics of PCF have been analyzed underconsideration of the influence factors of cladding air hole’s diameter and pitch. Bychanging the air hole’s size, the nonlinear coefficient can be effectively changed, thezero-dispersion wavelength was also changed and the mode birefringent was influenced.Another birefringent PCF with elliptical core and four large hole was designed. Thus itprovides a theoretical basis for supercontinuum in high nonlinear and birefringent PCF.Secondly, in capillary drawing process, the relationship among collapse withtemperature, send rod speed, drawing speed and air filling rate have been investigated. Aneffective method was proposed to improve the problem of collapse. The improvedstacking method was proposed to manufacture PCF with special structures. And the PCFwith high nonlinear and birefringent was successfully prepared.Finally, the PCF with high nonlinear and birefringent made by myself wereinvestigated experimentally using femtosecond laser pulses in normal dispersion. Thepulse broadening phenomena was investigated under different center wavelength, differentaverage power, different deflection angle of incident pulse and different fiber length. Andthe mechanism of supercontinuum of the PCF with high nonlinear and birefringent wasanalyzed in normal dispersion.