Diffraktiomalli

Diffraktiomalli is a Finnish term that translates to “diffraction model” in English. It refers to theoretical frameworks used to describe and predict the scattering of waves—typically electromagnetic, acoustic, or quantum fields—by obstacles or apertures. In physics, diffraction occurs when a wavefront encounters an obstacle that is comparable in size to its wavelength, resulting in characteristic interference patterns such as the Airy disk or the Fraunhofer and Fresnel diffraction patterns.

The concept of diffraction modeling arose in the early 19th century with the work of Augustin-Jean Fresnel, who formalised the wave theory of light. Over the twentieth century, mathematicians and engineers extended Fresnel’s work to electromagnetic wave propagation, leading to the development of the Kirchhoff and Rayleigh–Sommerfeld diffraction integrals. Modern diffraktiomallit incorporate numerical methods such as the finite-difference time-domain (FDTD) technique, the method of moments, and the physical optics approximation to handle complex geometries and inhomogeneous media.

Applications of diffraktiomallit are diverse. In optics they support the design of lenses, interferometers, and optical fiber systems. In acoustics they aid in architectural acoustics and sonar technology. In quantum mechanics, they help in the analysis of electron diffraction and the interpretation of diffraction experiments in crystallography. The accuracy of a diffraktiomalli depends on simplifying assumptions, such as the scalar approximation or the far-field condition, and on the quality of input data such as material refractive indices or boundary shapes.