Two-Element Refracting System for Annular Gaussian-to-Bessel Beam Transformation.

Area of Science:

• Optics and Photonics
• Laser Physics
• Optical Engineering

Background:

• Annular Gaussian beams are useful but tend to diffract.
• Bessel beams exhibit non-diffracting properties, ideal for specific applications.
• Transforming beam profiles efficiently is a key challenge in laser optics.

Purpose of the Study:

• To design a refractive optical system for converting annular Gaussian laser beams into circular Bessel beams.
• To achieve a long diffraction-free propagation distance for the generated Bessel beam.
• To ensure the optical surfaces are manufacturable.

Main Methods:

• A two-lens refracting system was designed.
• Input and output surface profiles were defined using sixth-order polynomials.
• Ray tracing and diffraction propagation simulations were likely employed (inferred).

Main Results:

• The system successfully transforms an annular Gaussian beam into a circular Bessel beam.
• The optical surfaces exhibit smooth variations in their radii of curvature.
• A diffraction-free length of 59.4735 meters was calculated for the system at a wavelength of 633 nm.

Conclusions:

• The designed two-lens system provides an effective method for generating circular Bessel beams from annular Gaussian beams.
• The use of sixth-order polynomial surfaces facilitates the fabrication of the aspheric lenses.
• The achieved long diffraction-free length demonstrates the system's potential for applications requiring non-diffracting beams.