Femtosecond tunable solitons up to 4.8 μm using soliton self-frequency shift in an InF3 fiber

A tunable ultrashort soliton pulse source reaching up to 4.8 & mu;m is demonstrated based on a 2.8 & mu;m femtosecond fiber laser coupled to a zirconium fluoride fiber amplifier followed by a small core indium fluoride fiber. This demonstration is extending by 300 nm the long wavelength limit previously reported with soliton self-frequency shift (SSFS) sources based on fluoride fibers. Our experimental and numerical investigation highlighted the spectral dynamics associated with the generation of highly redshifted pulses in the mid-infrared using SSFS enhanced by soliton fission. This study is intended at providing a better understanding of the potential and limitations of SSFS based tunable femtosecond fiber sources in the 3-5 & mu;m spectral range.

Automated summary

This study demonstrates a tunable ultrashort soliton pulse source capable of reaching up to 4.8 μm. By coupling a 2.8 μm femtosecond fiber laser to a zirconium fluoride fiber amplifier and a small core indium fluoride fiber, it extends the wavelength limit previously reported with soliton self-frequency shift (SSFS) sources based on fluoride fibers. The experimental and numerical investigation reveals the spectral dynamics associated with the generation of highly redshifted pulses in the mid-infrared using SSFS enhanced by soliton fission. This research aims to provide a better understanding of the potential and limitations of SSFS-based tunable femtosecond fiber sources in the 3-5 μm spectral range.