An all-fiber mid-infrared (6 – 9 µm) source based on difference frequency generation in OP-GaP crystal

Abstract

We present an all-fiber source generating laser pulses in the 6 - 9 μm spectral range. The developed setup is based on difference frequency generation (DFG) in an orientation-patterned gallium phosphide (OP-GaP) with six different quasi-phase matching (QPM) periods. The maximum 7.4 mW average output power of the idler centered at 7600 nm was obtained with the 7% photon conversion efficiency.