Numerical simulations of the ultrabroadband supercontinuum generation by dual-wavelength pumping in photonic crystal fiber with two zero dispersion wavelengths.

Ultrabroadband supercontinuum has received considerable attention due to its numerous applications in practice. An ultrabroadband supercontinuum spanning from 426 to 2954 nm is generated numerically in this paper. It is achieved by dual-wavelength pumping with a specially designed silica photonic crystal fiber that has two widely separated zero dispersion wavelengths. Additionally, the wavelengths of dual-wavelength pumping are both located in the anomalous dispersion regime in our investigation, which differs from research ever reported. Detailed physical mechanisms as well as interaction between the injected two pulses are discussed explicitly. With the introduction of a second pump pulse in the infrared region, a blueshifted dispersive wave is excited, turning out to be advantageous to extend a supercontinuum further into ultraviolet. Interestingly, the infrared edges remain unchanged whether a pulse in near infrared is added or not. The pulse synchronization issue is studied thoroughly and the conclusion that the two pulses can encounter within the used fiber length is declared.