Generation of vector polarization in a Nd:YAG laser

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Generating vector laser beams with specific polarization states is crucial for advanced optical applications.
• Traditional methods for producing azimuthally and radially polarized beams can be complex and inefficient.

Purpose of the Study:

• To demonstrate a novel method for generating azimuthally and radially polarized beams in a Nd:YAG laser.
• To investigate the efficiency and beam quality of the generated vector beams.
• To explore a simple technique for interconverting between azimuthal and radial polarizations.

Main Methods:

• Utilized a Nd:YAG laser system incorporating a birefringent c-cut yttrium vanadate (YVO4) crystal as an intra-cavity polarization discriminator.
• Employed controlled input pump power to achieve mode selection and polarization control.
• Characterized the output power, optical-to-optical efficiency, and beam quality (M² factor) of the generated beams.

Main Results:

• Successfully generated both azimuthally polarized (AP) and radially polarized (RP) laser beams.
• Achieved output powers of 2.4W for AP (35.4% efficiency, M² = 2.3) and 2.52W for RP (37.2% efficiency, M² = 2.4) at an absorbed pump power of 6.78W.
• Demonstrated a straightforward method for switching between AP and RP by adjusting the input pump power.

Conclusions:

• The developed Nd:YAG laser system effectively generates high-quality azimuthally and radially polarized beams.
• The simple pump power modulation technique allows for facile conversion between polarization states.
• This vector laser technology holds significant potential for various scientific and industrial applications requiring tailored polarization.