Numerical demonstration of enhanced mid-infrared dispersive wave generation

We demonstrate theoretically the enhanced mid-infrared dispersive waves (MIR-DWs) generation in erbium-doped fluoride fibers with two zero-dispersion wavelengths (ZDWs). This model includes Raman soliton generation, soliton self-frequency shift (SSFS), soliton gain, and DW generation. Making full use of the gain bandwidth of Er³⁺ and the SSFS effect to amplify soliton energy and then radiate enhanced MIR-DW. We compare results obtained in different gain fluoride fibers, DW energy is increased by up to 45 times, and the soliton-DW conversion efficiency is increased from 51.3% to 94% by applying a 10 dB/m peak gain in a 3.5 μm core diameter fluoride fiber. Further, we design different dispersion curves by changing the core diameter and obtaining different wavelength DWs ranging from 3.3 to 4.4 μm. Our results highlight the potential of the new technology in efficiently obtaining arbitrary wavelength MIR ultrashort pulse lasers, breaking through the limitation of rare rare-earth ion gain region.