Efficiency-enhanced picosecond mid-infrared optical parametric downconversion based on a cascaded optical superlattice

We demonstrate an efficiency-enhanced picosecond(ps) mid-infrared radiation via optical parametric downconversion. Based on a ceiscaded periodically poled MgO-doped stoichiometric lithium tantalate crystal(MgO:sPPLT), a tandem optical parametric oscillation-optical parametric amplification(OPO-OPA) process is achieved. Compared with a single OPO process, the conversion efficiency obtains an enhancement of 71%.