Electromagnetic diffraction theory of refractive axicon lenses

Area of Science:

• Optics and Photonics
• Electromagnetic Theory

Background:

• Axicon lenses are crucial for generating non-diffracting beams.
• Understanding beam propagation is essential for optical system design.

Purpose of the Study:

• To compare optical field predictions from geometrical optics, scalar wave optics, and electromagnetic diffraction theory for a paraxial refractive axicon.
• To analyze the influence of incident beam polarization on the generated optical field.

Main Methods:

• Comparative analysis of theoretical frameworks: geometrical optics, scalar wave optics, and electromagnetic diffraction theory.
• Rigorous electromagnetic diffraction analysis of the paraxial refractive axicon field.
• Examination of axial intensity, on-axis effective wavelength, transverse intensity, and far-zone field.

Main Results:

• Electromagnetic diffraction theory provides a more complete description than geometrical or scalar wave optics.
• The polarization state of the incident beam significantly alters the transverse intensity distribution.
• Far-zone intensity distribution remains independent of the incident beam's polarization.

Conclusions:

• Polarization effects are critical for understanding near-field characteristics of axicon-generated beams.
• The far-field behavior is robust against polarization changes, simplifying some applications.