Researchers diffract a beam of organic molecules

A team of researchers from Austria, Germany, and the U.K. has succeeded in diffracting a beam of organic molecules. In their paper published in the journal Physical Review Letters, the researchers describe demonstrating Bragg ...

Fast and flexible computation of optical diffraction

Diffraction is a classic optical phenomenon accounting for light propagation. The efficient calculation of diffraction is of significant value towards the real-time prediction of light fields. The diffraction of electromagnetic ...

New insights into van der Waals materials found

Layered van der Waals materials are of high interest for electronic and photonic applications, according to researchers at Penn State and SLAC National Accelerator Laboratory, in California, who provide new insights into ...

Researchers solve a 60-year-old puzzle about a superhard material

Skoltech researchers, together with their industrial colleagues and academic partners, have cracked a 1960s puzzle about the crystal structure of a superhard tungsten boride that can be extremely useful in industrial applications, ...

A new way to study how elements mix deep inside giant planets

There are giants among us—gas and ice giants to be specific. They orbit the same star, but their environmental conditions and chemical makeup are wildly different from those of Earth. These enormous planets—Jupiter, Saturn, ...

Multicolor super-resolution imaging made easy

Scientists at EPFL have developed robust and easy-to-implement multicolor super-resolution imaging. The approach is based on the simultaneous acquisition of two spectral channels followed by spectral cross-cumulant analysis ...

Fiber imaging beyond the limits of resolution and speed

Researchers at ARCNL and Vrije Universiteit Amsterdam have developed a compact setup for fast, super-resolution microscopy through an ultrathin fiber. Using smart signal processing, they beat the theoretical limits of resolution ...

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Diffraction

Diffraction refers to various phenomena which occur when a wave encounters an obstacle. Italian scientist Francesco Maria Grimaldi coined the word "diffraction" and was the first to record accurate observations of the phenomenon in 1665. In classical physics, the diffraction phenomenon is described as the apparent bending of waves around small obstacles and the spreading out of waves past small openings. Similar effects occur when light waves travel through a medium with a varying refractive index or a sound wave through one with varying acoustic impedance. Diffraction occurs with all waves, including sound waves, water waves, and electromagnetic waves such as visible light, x-rays and radio waves. As physical objects have wave-like properties (at the atomic level), diffraction also occurs with matter and can be studied according to the principles of quantum mechanics.

Richard Feynman said that

He suggested that when there are only a few sources, say two, we call it interference, as in Young's slits, but with a large number of sources, the process is labelled diffraction.

While diffraction occurs whenever propagating waves encounter such changes, its effects are generally most pronounced for waves where the wavelength is roughly similar to the dimensions of the diffracting objects. If the obstructing object provides multiple, closely spaced openings, a complex pattern of varying intensity can result. This is due to the superposition, or interference, of different parts of a wave that traveled to the observer by different paths (see diffraction grating).

The formalism of diffraction can also describe the way in which waves of finite extent propagate in free space. For example, the expanding profile of a laser beam, the beam shape of a radar antenna and the field of view of an ultrasonic transducer can all be analysed using diffraction equations.

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