Selection rule for cavity configurations to generate cylindrical vector beams with low beam quality factor

Area of Science:

• Laser Physics
• Optical Engineering
• Photonics

Background:

• Generating high-quality cylindrical vector (CV) laser beams is crucial for applications like optical trapping and microscopy.
• Cavity design significantly influences the polarization and beam quality of laser output.
• Birefringence in the gain medium presents challenges for controlling laser beam polarization.

Purpose of the Study:

• To propose a selection rule for designing laser cavity configurations.
• To enable the generation of radially and azimuthally polarized laser beams with high beam quality.
• To demonstrate the versatility of stable cavity regions in supporting CV beams.

Main Methods:

• Developing a selection rule based on the birefringence of the gain medium.
• Utilizing the end mirror position as a tuning parameter to vary cavity configurations.
• Performing theoretical analyses and numerical simulations.
• Conducting experimental measurements of beam quality factor and polarization characteristics.

Main Results:

• A selection rule was proposed and validated for designing laser cavities.
• Stable cavity regions were shown to support cylindrical vector (CV) beams.
• Radially and azimuthally polarized beams were generated by tuning the cavity configuration.
• Experimental verification confirmed the analyses and simulations for a four-element laser system.

Conclusions:

• The proposed selection rule effectively guides the design of laser cavities for high-quality CV beam generation.
• Cavity configuration tuning, specifically end mirror positioning, is a reliable method for obtaining desired polarization states.
• The findings offer a practical approach for producing tailored laser beams for various scientific and technological applications.