Syncronous generation of nanosecond pulses at 1064 nm and 1240 nm in all-fiber laser

Generation of two synchronized pulses with broadly different wavelengths in the same fiber laser cavity opens up promising possibilities of entering the mid-IR wavelength range by difference frequency generation (DFG). One of the ways to generate synchronous pulses with very different wavelengths is Raman conversion in a P
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-doped fiber incorporated into the laser cavity in addition to an Yb-doped fiber. This work demonstrates, for the first time, efficient generation of synchronized pulses at wavelengths of 1064 and 1240 nm in such an all-fiber nested-cavity laser. An external DFG stage allows conversion of the laser output into pulsed radiation at ~7.5 µm.