Metasurface-assisted orbital angular momentum carrying Bessel-Gaussian Laser: proposal and simulation

Area of Science:

• Optics and Photonics
• Laser Physics
• Metamaterials

Background:

• Bessel-Gaussian beams exhibit unique properties like suppressed diffraction and self-reconstruction.
• Orbital angular momentum (OAM) offers advanced light manipulation capabilities.

Purpose of the Study:

• To propose and simulate a metasurface-assisted laser generating OAM-carrying Bessel-Gaussian beams.
• To investigate the feasibility and performance of such a laser system.

Main Methods:

• A Fabry-Perot cavity was designed using a metasurface reflector and a partially transparent output mirror.
• Nd:YVO4 gain medium at 1064 nm, pumped by an 808 nm laser, was employed.
• Metasurface provided combined axicon and spherical mirror phase functions for spatial light manipulation.

Main Results:

• Achieved high fidelity lasing modes: Bessel-Gaussian0 (~0.889), Bessel-Gaussian01+ (~0.889), Bessel-Gaussian02+ (~0.881), and Bessel-Gaussian03+ (~0.879).
• Demonstrated flexible spatial light manipulation using the metasurface's sub-wavelength structure.
• Analyzed metasurface fabrication tolerance and performance dependencies (threshold power, output power) on various parameters.

Conclusions:

• Successfully implemented a metasurface-assisted OAM-carrying Bessel-Gaussian laser with favorable performance.
• The developed laser system shows potential for diverse OAM-enabled communication and non-communication applications.