Self-healing highly-chirped fiber laser at 1.0 μm

We demonstrate a MHz wavelength-swept fiber laser with diffraction-free and self-healing properties at the bio-favorable wavelength window of 1.0 μm. This ultrafast wavelength sweeping at a high chirp rate is all-optically realized through a newly-designed dispersive fiber that can provide a dispersion amount up to -1.7 ns/nm. It is 8 times larger than the standard single-mode fiber at this window and by adopting a double-pass configuration, the dispersion amount can be further increased to about -3.5 ns/nm, which is 23 times larger than what has previously been demonstrated. Its beam profile, a 2D Airy function, shows no obvious diffraction within a propagation distance of 2 meters and furthermore, the self-healing property is also verified by blocking the main lobe of the laser beam. This is the first wavelength-swept fiber laser equipped with diffraction-free and self-healing properties at the bio-favorable window. We believe that such effort can enable real-time data processing and a deeper penetration for the high-speed spectroscopic applications in the turbid environment.