Numerical Analysis of Supercontinuum Generation in Tapered Photonic Crystal Fiber

The spectrum generated in tapered Photonic Crystal Fiber (PCF) by ultrashort laser pulses is demonstrated via means of numerical simulations of the generalized Nonlinear Schrdinger Equation. Our simulations are able to deliver the spectral evolution of the pulses along the fiber axis at desired propagation distances. Differences of the output spectra and the propagation of laser pulses depending on the different structures of the PCF tapers are investigated. The results show that the variation of the diameter of a tapered PCF along the fiber axis crucially influences the soliton dynamics, the spectral evolution as well as the generation of a supercontinuum (SC). The diameter of a tapered fiber along the fiber axis can be used as a new degree of freedom to tailor the spectrum generated by ultrashort laser pulses.