Photonics Dictionary

Holography is a technique used to capture and reconstruct three-dimensional images using the principles of interference and diffraction of light. Unlike conventional photography, which records only...

The optical reconstruction of image information contained in a sound field. First the diffraction pattern, formed by an object irradiated by ultrasonic rays, interferes with a mutually coherent...

The recording of three or more separate holograms having a different color on a medium, so that illumination with a tricolor beam yields three separate wavefronts, each representing one of the...

A technique used to store wavefront information on thin polarization information-recordable materials by controlling the polarization angle of a small illuminating spotlight in each sampling cell on...

The formation of an interferogram by means of two holograms on the same recording medium, often used for determining small changes in an object. One hologram produces a primary image that constitutes...

Holographic recording whereby the object is illuminated by two pulses, separated by a time interval, from a Q-switched laser source. Each pulse is divided into reference and object beams, and...

A technology that uses electrically activated holograms stored within specially developed crystals to route information in the form of lightwave signals from one optical fiber to another within and...

The holographic recording of sequences of high-speed phenomena. With a multiple beam laser, multiple holograms that depict rapid events can be formed on a single medium.

A hologram in which the image of an object, or the object itself, is located near the hologram recording plane, for optimum image reconstruction. Because the images are close to the hologram plane,...

The formation of a hologram by single reference-beam interferences with waves that are diffracted or scattered from a small object.

The production of holograms initially from either conventional photographs or incoherent optical equipment.

The acoustical holographic process in which the hologram consists of slight elevations in a liquid surface, in the areas of the antinodes of the interference pattern. Light diffracted from this...

The holographic recording of the pattern formed by two sets of coherent microwaves that interfere at a scanning plane. A scanning device converts the microwave interference pattern into a light...

A lithography method that allows the transfer of fine-pitch gratings from a phase mask into photoresist. The exposure takes place with the light coming under an oblique angle to the mask. The...

A technique proposed for studying the atomic structure of crystals by measuring the interference pattern generated when the crystal is illuminated by a burst of finely tuned x-rays. The resulting...

Separation of incident laser pulses by several seconds so holographic plates can be changed and sandwiched between the pulses. This technique combines the short exposure time of pulsed holography...

The simultaneous exposure of two holographic plates with emulsions facing the object. After deformation, a second pair of plates is exposed to the deformed object. The back plate of the initial pair...

Although low in sensitivity (approximately 10-7 m for helium-neon lasers), this holographic technique permits quantitative assessment of entire vibratory patterns of given structures in a single...

A photorefractive material used in image processing, holography and optical switching.

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

Digital holographic microscopy (DHM) is an advanced imaging technique that combines holography and digital image processing to capture and reconstruct three-dimensional images of objects. This method...

A method for detecting vibration amplitudes analogous to image holography, except that the film emulsion is replaced by a television target.

A technique used in holography that involves the mixing of lasers of different wavelengths to produce a beam of shorter wavelength.

A helium-neon (HeNe) laser is a type of gas laser that emits visible red light at a wavelength of 632.8 nm. It operates based on the principle of stimulated emission of photons from excited helium...

A holographic camera, also known as a holographic imaging system or holographic recorder, is a specialized device used to capture 3D holographic images of objects or scenes. Unlike conventional...

A holographic grating is a type of diffraction grating that is produced using holographic recording techniques. It consists of a periodic structure of alternating transparent and opaque regions,...

Holographic tomography is an advanced imaging technique that combines holography and tomography to provide three-dimensional reconstructions of transparent or weakly scattering objects with high...

Lensless microscopy, also known as computational or holographic microscopy, is an imaging technique that captures and reconstructs microscopic images without the use of traditional lenses. Instead of...

A liquid crystal light valve (LCLV), also known as a spatial light modulator (SLM), is an optical device that modulates the intensity, phase, or polarization of light passing through it using liquid...

Metasurfaces are two-dimensional arrays of subwavelength-scale artificial structures, often referred to as meta-atoms or meta-elements, arranged in a specific pattern to manipulate the propagation of...

In holography, the wave of light that illuminates the object to be recorded, which diffracts it to the recording medium, where it interferes with the reference beam, generating the hologram.

The storage of information via optical means, primarily employing a low-power laser to inscribe data on a photosensitive surface as pits or phase differences and to read such data via reflected light...

In optics and photonics, "phase" refers to a property of electromagnetic waves, such as light, that describes the position of a wave at a given point in time within its oscillation cycle. More...

In optics and photolithography, a phase mask refers to a device that modifies the phase of light waves passing through it. The phase mask is used to control the spatial distribution of the light's...

A phase screen, in the context of optics and wave optics, refers to a surface or medium that introduces a phase delay to an incident wavefront passing through it. This concept is often used in the...

Quantitative phase imaging (QPI) is an advanced imaging technique used in microscopy to measure and analyze the optical phase information of transparent specimens. Unlike traditional brightfield...

In holography, the beam of light that is directed from the beamsplitter to the recording medium, where it interferes with the object beam to generate the hologram.

A spatial light modulator (SLM) is an optical device that modulates or manipulates the amplitude, phase, or polarization of light in two dimensions, typically in the form of an array. SLMs are...

Short-distance scattering of light in holography caused by random index inhomogeneities and the developing index that interferes with the incident beam, thus recording a hologram of the scattered...