High-power mid-infrared wavelength generation using difference frequency generation in damage-resistant Zn:LiNbO 3 waveguide

High-power 3.4 µm difference frequency generation (DFG) using a quasi-phase-matched Zn:LiNbO3 waveguide fabricated by direct bonding technology is presented. The high resistance of the waveguide to photorefractive damage allows high-power generation. A 65 mW mid-infrared output was obtained using a continuous-wave high-power fibre amplifier as pump source. The DFG source can access over 10 nm continuously simply by scanning the signal wavelength, and will be useful for real-time trace gas sensing.