Efficiency-enhanced optical parametric down conversion for mid-infrared generation on a tandem periodically poled MgO-doped stoichiometric lithium tantalate chip

Abstract

We report an efficiency-enhanced mid-infrared generation via optical parametric down conversion. A tandem periodically-poled MgO-doped stoichiometric lithium tantalate crystal is used to realize on-chip generation and amplification of mid-infrared radiation inside an optical parametric oscillator cavity. We achieved 21.2% conversion efficiency (24% slope efficiency), which is among the highest efficiencies for the pump-to-mid-infrared conversion, with 1064 nm Nd class laser pump. The maximum average output power at 3.87 μm reached 635 mW with a 3.0 W pump.