title: Tunable 2-μm optical vortex parametric oscillator.
abstract: We generated tunable 2-μm optical vortex pulses with a topological charge of 1 or 2 in the wavelength range 1.953-2.158 μm by realizing anisotropic transfer of the topological charge from the pump beam to the signal output in a vortex-pumped half-symmetric optical parametric oscillator. A maximum vortex output energy of 2.1 mJ was obtained at a pump energy of 22.8 mJ, which corresponds to a slope efficiency of 15%. The topological charges of the signal and idler output were investigated using a shearing interferometric technique employing a low-spatial-frequency transmission grating.
authors.affiliation: Graduate School of Advanced Integration Science, Chiba University, Chiba 263-8522, Japan.
authors.forename: Taximaiti
authors.initials: T
authors.lastname: Yusufu
authors.forename: Yu
authors.initials: Y
authors.lastname: Tokizane
authors.forename: Masaki
authors.initials: M
authors.lastname: Yamada
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Takashige
authors.initials: T
authors.lastname: Omatsu
mesh_terms: D000669:Amplifiers, Electronic; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D009991:Oscillometry / Q000295:instrumentation*