High average power supercontinuum generation in a fluoroindate fiber

We report the first demonstration of Watt-level supercontinuum (SC) generation in a step-index fluoroindate (InF 3 ) fiber pumped by a 1.55 μm fiber master-oscillator power amplifier (MOPA) system. The SC is generated in two steps: first ∼1 ns amplified laser diode pulses are broken up into soliton-like sub-pulses leading to initial spectrum extension and then launched into a fluoride fiber to obtain further spectral broadening. The pump MOPA system can operate at a changeable repetition frequency delivering up to 19.2 W of average power at 2 MHz. When the 8-m long InF 3 fiber was pumped with 7.54 W at 420 kHz, output average SC power as high as 2.09 W with 27.8% of slope efficiency was recorded. The achieved SC spectrum spread from 1 to 3.05 μm.