Supercontinuum generation in single crystal sapphire fibers

摘要

Novel supercontinuum generation by launching ultra-short femtosecond laser pulses into single crystal sapphire fibers is demonstrated. Supercontinuum generation using sapphire fiber exhibits many advantages that include high transparency up to 5 micron, low material dispersion in the 0.8 micron to 5 micron spectral range, and an extremely high laser damage threshold (500 times higher than that of silica). Thus, supercontinuum spectrum with high power, super broadband, and spatial coherence can be realized by pumping single crystal sapphire fibers. By experimental comparison, we prove that sapphire fiber can provide a broader supercontinuum spectrum than that of bulk sapphire counterpart under the same exciting conditions. Since supercontinuum generation in single crystal sapphire fibers can radiate high power supercontinuum in the middle-IR regime, it will have a great impact on many applications, including sensing and broadband multi-spectrum free space communications.