Does orbital angular momentum have effect on laser's scattering by molecular atmosphere?

Area of Science:

• Optics and Photonics
• Atmospheric Science
• Computational Physics

Background:

• Lasers with orbital angular momentum (OAM) offer advanced applications in communication, sensing, and particle manipulation.
• Understanding OAM laser interaction with atmospheric molecules is crucial for reliable transmission in these applications.

Purpose of the Study:

• To investigate the light-scattering properties of OAM Laguerre-Gaussian (LG) beams interacting with small dielectric particles in a molecular atmosphere.
• To determine if OAM affects light scattering in a way that impacts atmospheric transmission.

Main Methods:

• Utilized the finite-difference time-domain (FDTD) method to simulate light scattering.
• Calculated scattering for purely azimuthal LG beams (radial mode number = 0) by small dielectric particles.
• FDTD method allowed for calculations with particles off the beam's central axis.

Main Results:

• OAM had minimal effect on the scattering phase function for very small particles and non-extreme topological charges.
• Rayleigh theory is applicable for calculating light scattering by atmospheric molecules with OAM lasers.
• OAM laser beam transmission through a molecular atmosphere is similar to that of a regular Gaussian beam.

Conclusions:

• The OAM of a laser does not significantly alter light scattering in a molecular atmosphere under typical conditions for small particles.
• OAM lasers are suitable for atmospheric applications without significant loss due to molecular scattering.
• Standard atmospheric propagation models for Gaussian beams can be applied to OAM lasers.