Numerical Study on the Supercontinuum Generation in an Active Highly Nonlinear Photonic Crystal Fiber With Flattened All-Normal Dispersion

摘要

- First to perform a numerical study on supercontinuum (SC) generation (SCG) based on an active highly-nonlinear photonic crystal fiber (HNL-PCF) in sub-ps regime - First to quantitatively analyze the following gain-induced effects in SCG: (1) Enhancement of energy spectral density of the SC spectrum by the combined effects of the amplification of the central wavelength contents and their nonlinear spectral broadening (2) Extension of the nonlinear interaction length by the recovery of the depleted peak-power of the SC pulse - First to comparatively analyze two energy-scaling schemes for SCG, utilizing (1) lumped amplifier followed by a passive-type HNL-PCF and (2) an active-type HNL-PCF - First to numerically demonstrate the effective amplification of a SC pulse without significant degradation of the spectral bandwidth and flatnessWe numerically study the dynamics of supercontinuum generation (SCG) in an ytterbium-doped highly nonlinear photonic crystal fiber (HNL-PCF) with flattened all-normal dispersion (FAND) in the sub-picosecond pulse regime. We discuss the enhancement of the energy spectral density and the recovery of the peak power depletion in the SCG process through the fiber in comparison with the SCG based on a passive-type counterpart. As a unique application of the novel characteristics of the active HNL-PCF with FAND, we also analyze the direct amplification of an SC pulse through it, showing that the incident SC pulse can be amplified by 10 dB without undergoing significant degradations in terms of spectral bandwidth and flatness. Our numerical investigations on the active HNL-PCF with FAND will be helpful for opening up new opportunities for fiber-based SCG technology in the sub-picosecond regime.