3.87 W nanosecond mid-infrared vortex generation from a PPLN optical parametric oscillator

We demonstrate a high-power wavelength-tunable nanosecond mid-infrared (MIR, 3-5 μm) vortex laser based on a singly resonant optical parametric oscillator (OPO). With a MgO:PPLN crystal pumped by a first-order vortex at 1064 nm, efficient orbital angular momentum (OAM) transfer was achieved from the pump to the idler, while the signal remained a Gaussian-like profile without OAM. By varying the crystal temperature, the idler wavelength was tuned from 3142 to 3442 nm. At 3442 nm, the idler delivered a record vortex output of 3.87 W with 0.84% root-mean-square (RMS) fluctuation over one hour. To our knowledge, this is the highest reported vortex power beyond 3 µm among oxide-based OPOs, providing a stable and practical source for MIR applications such as spectroscopy, imaging, and material processing.