Numerical demonstration of mid-infrared soliton self-frequency shift in chalcogenide microstructured fiber

Abstract

Compact optical devices with an output wavelength range of more than 3 μm are limited due to the requirements of proper material and structural design. In this study, the phenomenon of a soliton self-frequency shift pumped by a femtosecond pulse in a chalcogenide microstructured fiber is investigated numerically. The structural parameters of the fiber are optimized to obtain far-separated zero-dispersion wavelengths at 2.24 µm and 5.34 µm with low confinement loss. A femtosecond tunable soliton with a frequency shifted up to 3.7 µm is achieved from a 10-cm long fiber with a conversion efficiency above 38.6 %, consuming a pump pulse energy of no more than 200 pJ at 2.8 µm, which is available from Er-doped fluoride fibers. Our work can provide an effective way to construct compact, all-fiber femtosecond tunable mid-infrared laser sources with low operation power.