Enhanced terahertz-wave parametric generation and oscillation in lithium niobate waveguides at terahertz frequencies

We observed parametric-generation efficiency of 1.61% from 1064 to 1071 nm and at 162 μm in a 0.5 mm thick, 45 mm long z-cut congruent lithium niobate waveguide with a pump energy of 2.2 mJ and a pump pulse width of 5.8 ns. We also measured an ultralow-threshold intensity of 70 MW/cm² for a 1064 nm pumped parametric oscillator resonating at 1071 nm and emitting at 162 μm with a 1 mm thick, 45 mm long lithium niobate waveguide.