Generation of spectral wings and temporal ultra-short pulse sequence

Abstract

We study the generation of supercontinuum (SC) with spectral wings and temporal ultra-short pulse sequence by pumping two identical time-delayed pulses in an all-normal dispersion fibre. The flat dispersion profile over the entire wavelength range of the generated SC provides an opportunity to divide these ultra-short pulses roughly evenly. By adjusting the time delay, the temporal width of these ultra-short pulses can be regulated considerably, which accelerates the development in numerous fields such as multi-photon microscopy and ultrafast spectroscopy. Besides, the temporal overlap of two pulses at different instantaneous frequencies leads to the emergence of spectral wings via four-wave mixing. By changing the input power and time delay, spectral wings with variable intensities and ranges can be emitted at different distances, which can expand the SC spectral bandwidth within a limited fibre length.