Widely-tunable mid-infrared (2.6–5 μm) picosecond vortex laser

We report on a widely-tunable mid-infrared picosecond optical vortex laser source that employs a synchronously-pumped optical parametric oscillator optimized for mid-infrared emission up to 5 μ m. Vortex output with a continuously-tunable wavelength range of 2.6–5 μ m could be obtained simply by translating the MgO:PPLN crystal. At the maximum pump power of 15 W, the maximum idler output powers were measured as 3.7, 1.7, and 0.165 W at the wavelengths of 2.6, 3.8, and 5 μ m, respectively. The corresponding photon conversion efficiencies were estimated to be 60% at 2.6 μ m, 40% at 3.8 μ m, and 5.2% at 5 μ m.