Near and mid-infrared optical vortex parametric oscillator based on KTA

Area of Science:

• Nonlinear Optics
• Laser Physics
• Photonics

Background:

• Optical vortex beams carry orbital angular momentum (OAM).
• Optical parametric oscillators (OPOs) are versatile laser sources.
• Efficient generation of high-energy vortex beams is crucial for various applications.

Purpose of the Study:

• To investigate the generation of high-energy optical vortex lasers in the near and mid-infrared.
• To demonstrate the selective transfer of OAM from a pump beam to the signal or idler output of an OPO.
• To characterize the energy, efficiency, and spectral properties of the generated vortex beams.

Main Methods:

• Utilized a 1 μm optical vortex-pumped potassium titanyl arsenate (KTiOAsO4, KTA) optical parametric oscillator.
• Manipulated output coupler reflectivity to control OAM transfer to signal or idler.
• Measured output energies, slope efficiencies, and spectral bandwidths (FWHM).

Main Results:

• Achieved 1.535 μm vortex signal output (2.04 mJ) and 3.468 μm vortex idler output (1.75 mJ).
• Obtained slope efficiencies of 14% for the signal and 10% for the idler.
• Measured spectral bandwidths of Δλs ≈ 1.3 nm and Δλi ≈ 1.7 nm.

Conclusions:

• Demonstrated a high-energy, tunable optical vortex laser system in the near and mid-infrared.
• Successfully transferred OAM from the pump to the OPO outputs.
• The developed KTA OPO system offers efficient generation of vortex beams for advanced optical applications.