Generating multiple optical vortices in orange beams induced by selectively pumped frequency-doubled solid-state...

Area of Science:

• Laser physics
• Nonlinear optics
• Photonics

Background:

• Solid-state lasers are crucial for generating specific light frequencies.
• Stimulated Raman scattering and second-harmonic generation are established techniques for frequency conversion.
• Optical vortices in laser beams have applications in areas like optical trapping and information transfer.

Purpose of the Study:

• To generate frequency-doubled lasing modes (FDLMs) at 588 nm using a solid-state laser.
• To transform FDLMs into structured beams with multiple optical vortices.
• To investigate the relationship between laser mode components, off-center pumping, and the generation of optical vortices.

Main Methods:

• Employing a selectively pumped solid-state laser system.
• Utilizing stimulated Raman scattering and second-harmonic generation for FDLM production.
• Using an external cylindrical mode converter to shape the FDLMs into structured beams.
• Conducting theoretical analysis and numerical reconstruction of experimental results.

Main Results:

• Successfully generated FDLMs at 588 nm.
• Transformed FDLMs into various structured beams containing multiple optical vortices.
• Established a clear correlation between the transverse displacement of off-center pumping and the laser emission's mode components.
• Demonstrated that the number of optical vortices can increase from 2 to 19 by adjusting the off-center displacement.

Conclusions:

• The study successfully demonstrates a method for generating tunable structured beams with multiple optical vortices.
• Theoretical models accurately predict and reconstruct the experimental outcomes for transformed FDLMs.
• Off-center pumping provides a controllable parameter for manipulating the topological charge and complexity of optical vortex beams.