Vektoridiffraktio

Vektoridiffraktio refers to the study of diffraction phenomena where the vector nature of light is essential. Unlike scalar diffraction theory, which treats the electric field as a single scalar amplitude, vector diffraction uses the full set of Maxwell’s equations to describe the three components of the electric field (and the accompanying magnetic field). This approach is necessary in regimes with high numerical aperture, tightly focused beams, or beams with structured polarization, where polarization coupling and longitudinal field components become significant.

The theoretical framework rests on vector diffraction integrals derived from the principles underlying diffraction and Maxwellian electromagnetism. Solutions describe how the electric field components propagate and interfere after passing through apertures or around obstacles. Practical computations commonly employ methods such as the angular spectrum method or numerical simulations like finite-difference time-domain (FDTD). Analytically, the diffracted field is expressed through Ex, Ey, and Ez, and polarization states are analyzed with tools such as Jones calculus or Stokes parameters.

Applications of vektoridiffraktio span several optical technologies. In high-NA microscopy and lithography, vector diffraction explains polarization effects and enhanced longitudinal fields. In optical trapping and nano-optics, it informs beam shaping and manipulation of particles. Vector beams with radial or azimuthal polarization illustrate how polarization structure influences focal properties and imaging performance.

History and development emerged from the need to extend scalar diffraction to regimes where polarization cannot be neglected. Vector diffraction remains a foundational concept in modern optics, complementing traditional diffraction theory and guiding design of advanced optical systems.

See also: Diffraction, Polarization, Vector fields.