Fibre coupled difference frequency generation utilisingytterbium-doped fibre amplifier and periodically poled LiNbO 3

Abstract
A new mid-infrared tunable spectroscopic source based on fibre coupled difference frequency generation in bulk periodically-poled LiNbO3 for trace gas detection is reported. The source mixes the outputs of a fibre coupled external cavity diode laser and a 1083 nm seeded Yb-doped fibre amplifier. Powers up to 0.8 µW are obtained in the 3.8 – 4.3 µm range.