Fresneldiffraktsiooni

Fresnel diffraction is a type of diffraction that occurs when a wave passes through an aperture or around an obstacle. It is named after the French physicist Augustin-Jean Fresnel, who first described the phenomenon in the early 19th century. Unlike Fraunhofer diffraction, which assumes the wavefront is planar and the observation point is at infinity, Fresnel diffraction takes into account the curvature of the wavefront and the finite distance between the source and the observation point.

Fresnel diffraction is often used to describe the propagation of light through small apertures, such as those found in optical instruments like microscopes and telescopes. It is also used to model the diffraction of sound waves, such as those produced by musical instruments or speech.

The Fresnel diffraction pattern is characterized by a series of bright and dark fringes, similar to those seen in Fraunhofer diffraction. However, the spacing and intensity of the fringes depend on the distance between the source and the observation point, as well as the size and shape of the aperture or obstacle.

Fresnel diffraction can be analyzed using mathematical techniques such as the Fresnel integral or the Fresnel zone plate. These techniques allow for the calculation of the diffraction pattern for a given set of parameters, and can be used to design optical systems that take advantage of diffraction effects.

In summary, Fresnel diffraction is a type of diffraction that occurs when a wave passes through an aperture or around an obstacle, taking into account the curvature of the wavefront and the finite distance between the source and the observation point. It is used in various fields, including optics and acoustics, and can be analyzed using mathematical techniques.