Research On Supercontinuum Generation By Femtosecond Pulse In Photonic Crystal Fibers

Photonic crystal fibers are developing based on photonic crystal technology as a new kind of fibers, it has three main advantages compare with traditional single mode fibers: a) It supports single mode transmission in a large frequency extension; b) It allows to change the effective area of fiber core, which in order to strengthen or weaken nonlinear effects, c) It can agile design the dispersion and dispersion slope of fibers, and agile change the zero dispersion wavelength. Photonic crystal fibers are good at supercontinuum generation and have a interesting foreground because of those advantages, its ability for supercontinuum generation exceed all other fibers and mediums. So the research of supercontinuum generation using photonic crystal fibers has become a hot topic in international recently years.In this article we solved the nonlinear Schrodinger equation with the method of split-step Fouior to simulate supercontinuum generation in photonic crystal fibers on different conditions, and gave a particular analysis. We got the main conclusions as below:1) We discussed the effect of different input pulses parameters on supercontinuum generation in photonic crystal fibers by the numbers. Include effect of peak power, center wavelength, pulses width and initial chirp. Higher peak power is profitable for supercontinuum generation; When center wavelength in the anomalous dispersion region, the case of supercontinuum generation is better evident than center wavelength in normal dispersion region, the farther from the zero dispersion wavelength, the broader spectral can be gained, but it is at the expense of flat. If center wavelength is extremely far from the zero dispersion wavelength, it will can't observe supercontinuum generation; The effect of pulse width is relatively complex, we must choose appropriate pulses width for different fibers by simulation again and again; initial chirp only affects spectrum at the initial broadening stage and the dramatic broadening stage, and the chirp is profitable for spectrum broadening when β₂C < 0, but the effect of chirp is opposite when β₂C > 0, at the saturation broadening stage, chirp will not affect the spectrum anymore.2) We discussed the effect of different fiber parameters on supercontinuum...