All-Fiber Mid-Infrared Enhanced Supercontinuum Generation in an Erbium-Doped ZBLAN Fiber Amplifier

We demonstrated all-fibermid-infrared enhanced supercontinuum generation in an Erbium-doped ZBLAN fiber amplifier. A 2 mu m low repetition rate noise like-pulse mode-locked fiber laser was adopted as the pulse seed for the system. After amplified in a Thulium-doped fiber amplifier, the noise like-pulse generated a supercontinuum covering the range from similar to 2 mu m to similar to 3.8 mu m in a piece of InF3 fiber. Then, the supercontinuum was injected into an Erbium-doped ZBLAN fiber amplifier as the seed for the next stage in-amplifier mid-infrared enhanced supercontinuum generation. A novel silica-fluoride fiber pump combiner was designed and fabricated to couple the 976 nm LD pump laser into the Erbium-doped ZBLAN fiber. The supercontinuum laser source realized mid-infrared enhancement and power boosting beyond 2.7 mu m in the Erbium-doped ZBLAN fiber amplifier. A similar to 1.4 W mid-infrared enhanced SC with long wavelength edge of similar to 4200 nm and 97% power beyond 2.7 mu m was obtained. This simple and compact all-fiber supercontinuum laser source has a great potential application in the 3-5 mu m molecular fingerprint region.