diffraktioa

Diffraktioa is the wave phenomenon in which waves bend around obstacles or spread as they pass through narrow openings, producing patterns of alternating high and low intensity due to interference. It is observed in many wave systems, including light, sound, and matter waves, and is a fundamental consequence of the superposition of waves.

The phenomenon can be explained using wave theory. The Huygens-Fresnel principle treats every point on a wavefront as a secondary source, with the resulting wavefield at a point being the sum of contributions from all points of the aperture or obstacle. In practical calculations, near-field (Fresnel) and far-field (Fraunhofer) approximations are used. For light, a common result for a single slit of width a is an intensity pattern I(θ) ∝ [sin(πa sin θ/λ) / (πa sin θ/λ)]^2. For two slits or a diffraction grating, the pattern combines interference with the single-slit envelope, yielding sharp maxima where the path difference is a multiple of the wavelength.

Diffraktioa is not limited to light. It also occurs with sound, water waves, and matter waves such as electrons and neutrons. In materials science, X-ray and electron diffraction are essential tools for probing crystal structures and surface properties. In optics, diffraction sets fundamental limits on image resolution, described by criteria such as the Rayleigh criterion and the Abbe limit. Diffraction effects are important in the design of optical instruments, spectroscopy, microscopy, and various wave-based technologies.