Stable donutlike vortex beam generation from lasers with controlled Ince-Gaussian modes.

Area of Science:

• Optics and Photonics
• Laser Physics
• Solid-State Lasers

Background:

• Generating controlled vortex laser beams is crucial for applications in optical trapping, microscopy, and information processing.
• Ince-Gaussian modes (IGMs) offer unique beam characteristics but achieving controlled operation, especially in donutlike vortex forms, remains challenging.
• Laser-diode (LD)-pumped solid-state lasers provide an efficient platform for generating various laser modes.

Purpose of the Study:

• To propose and demonstrate a simple, easily manufactured three-lens configuration for generating stable donutlike vortex laser beams.
• To achieve controlled Ince-Gaussian mode (IGM) operation within a laser-diode-pumped solid-state laser system.
• To investigate the effect of pump beam focus position on the generated vortex beam characteristics.

Main Methods:

• A three-lens optical configuration was designed and implemented.
• An integrated astigmatic mode converter was incorporated into a concave-convex laser cavity.
• The lateral off-axis position of the pump beam's focus on the laser crystal was systematically varied.

Main Results:

• A stable donutlike vortex laser beam with controlled IGM operation was successfully generated.
• The proposed three-lens configuration proved effective in producing the desired vortex beam.
• Simple adjustment of the pump beam's focus position enabled precise control over the generated beam properties.

Conclusions:

• The proposed three-lens configuration offers a straightforward and effective method for generating controlled donutlike vortex laser beams.
• This technique facilitates tunable IGM operation in LD-pumped solid-state lasers, expanding their applicability.
• The simplicity and ease of implementation make this configuration attractive for practical laser systems.