Efficient mid-infrared dispersive wave generation through soliton breakup and cascaded Raman amplification in an axially varying fluorotellurite fiber

Abstract

In this paper, we demonstrate efficient mid-infrared dispersive wave (DW) generation through soliton breakup and cascaded Raman amplification in an axially varying fluorotellurite fiber. The input part of the fluorotellurite fiber has two zero-dispersion wavelengths and the remaining part has an all normal dispersion profile. The pump source is a femtosecond fiber laser with an operational wavelength of 1980nm, which is located at the anomalous dispersion region between two zero-dispersion wavelengths and close to the second zero-dispersion wavelength of the fluorotellurite fiber. As the pump light is launched into the fluorotellurite fiber, the pump light (or a higher-order soliton) experiences a temporal breakup and large pulse broadening, which enables nearly complete conversion of input solitonic radiation into resonant nonsolitonic radiation in the DW regime. Meanwhile, the generated DWs are improved by more than two orders of magnitude via cascaded Raman amplification in the fluorotellurite fiber, resulting in the generation of efficient mid-infrared DWs peaked at 2700 nm with an ultrahigh power division ratio of ∼ 85% and a compressible pulse width of ∼ 61 fs. Our work presents a way to realize ultrahigh-efficiency mid-infrared coherent light generation.