IR tunable narrow-band nanosecond converter with a microchip pump source and periodically-poled Lithium Niobate

We report a compact nanosecond source based on optical parametric generation in a periodically-poled Lithium Niobate slab pumped with a Nd3+:YAG/Cr4+:YAG microchip laser at the wavelength 1.064 μm and capable of generating a diffraction-limited beam widely tunable through the mid-IR. The device efficiency is shown to reach 30% at relatively low (units of μJs) pump pulse energy and its spectrum to be narrowed down to 0.2 nm using low-power CW seed provided by a DFB laser.