Photonics Dictionary: D

As a wavefront of light passes by an opaque edge or through an opening, secondary weaker wavefronts are generated, apparently originating at that edge. These secondary wavefronts will interfere with...

The angle that lies between the direction of an incident light beam and any resulting diffracted beam.

Diffraction efficiency is a measure of how effectively a diffractive optical element (DOE) or diffraction grating directs light into specific diffraction orders or achieves a desired optical effect....

The formation of a fan of light or energy rays in a beam as the beam passes through an extremely narrow aperture.

A spectrograph that uses a diffraction grating as its dispersive element in place of a prism, and yields greater resolving power, more dispersion and a linear spectrum.

A diffraction grating is an optical component consisting of a surface with a periodic structure of equally spaced, parallel grooves or rulings. These rulings act as an array of closely spaced slits...

The property of an optical system whereby only the effects of diffraction determine the quality of the image it produces.

The interference pattern formed by light waves diffracted at the edges of an object as seen on a screen placed in their path.

1. The ring patterns of light that seem to encircle particles in the field of a microscope. 2. See Newton's rings.

Elastic scattering that occurs when inelastic processes eliminate particles from the beam.

In spectroscopy, the parallel bands that vary in lightness and darkness or color, and that are formed when light is diffracted by a sample.

A lens with aberrations corrected to the point that residual wavefront errors are substantially less than one-quarter the wavelength of the energy being acted upon.

A device used in ultrasonic imaging to measure the velocity and attenuation of compressional waves in a transparent liquid by virtue of acoustic waves set up in the liquid. The wavefronts serve as a...

Any bending of a wave of radiation away from its expected path, as, for example, by diffraction or by a magnetic field.

A shallow, fine-pitch diffraction grating having a precise dielectric overcoating that experimentally has absorbed wavelength-specific incident light that is polarized in the P-plane.

Differential interference contrast (DIC) microscopy, also known as Nomarski interference contrast microscopy, is an optical imaging technique used in microscopy to enhance the contrast of transparent...

Any optical device that utilizes diffraction in an image-forming capability. Familiar diffractive lenses are zone plates, holographic lenses, kinoform lenses and binary optics.

Optical elements that use diffraction to control wavefronts. Diffractive optical elements include diffraction gratings, surface-relief diffractive lenses, holographic optical elements and...

A measurement device used to study the structure of matter using the diffraction of electromagnetic radiation.

The study of the diffraction of beams of a wave by matter to ascertain the structure of the matter.

A pair of long, slender parallel apertures used in experiments on diffraction and interference.

The theoretical explanation and analysis of the interactions between electron waves and crystals used in studying electron diffraction.