Photonics Dictionary: H

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 high-speed motion camera, also known as a high-speed camera or slow-motion camera, is a specialized imaging device designed to capture fast-moving events or phenomena at extremely high frame rates....

A camera designed to record at rates exceeding 50 fps. For frame rates up to about 500 fps, an ordinary pull-down mechanism can be used. From 500 to 1000 fps, the film must be moved continuously, the...

Photography involving the recording of events that occur too fast to be perceived by the human eye or recorded by conventional photographic techniques. See high-speed movie camera; high-speed...

A method of producing x-ray exposures as short as 0.03 µs; the primary application is in ballistic radiography.

A shutter actuated by means other than mechanical springs for timings on the order of nanoseconds. The shutter is used in the photography of rapid moving objects or events.

A still camera with a shutter capable of opening for a time as short as a fraction of a microsecond. An electronically operated Kerr cell often is employed.

An imaging device whose technology contributes three specific advantages: ability to study large solid specimens that exhibit behavior in bulk; conduction of in situ studies of radiation damage; and...

The portion of a reproduced image having the greatest luminance.

A fish-eye lens designed to photograph cloud formations over the entire visible sky.

A system of Japanese origin that utilizes Fresnel lenses and a fiber optic network to transmit sunlight to otherwise inaccessible areas.

A null optic in the form of a concave spherical mirror; used for the test and evaluation of a hyperboloidal aspheric surface.

Histochemical staining is a laboratory technique used in biology and medicine to visualize specific chemical components within biological tissues. This technique involves the application of various...

A graphic representation of a distribution function such as frequency by means of rectangles whose widths represent the intervals into which the observed values' range is divided and whose heights...

Histology is the branch of biology and medicine that involves the study of the microscopic structure of tissues and organs at the cellular and subcellular levels. It is a field that focuses on the...

Techniques used in biology to produce microradiographs of cells, tissues or small organisms.

The dip or gap in the profile of a laser beam's line width when it is both homogeneously and inhomogeneously broadened. When an inhomogeneously broadened spectral line is saturated by incident light,...

An infrared-transmitting optical fiber with a hollow core; it can be square, round or rectangular in cross section. Capable of carrying high laser power but subject to high bending losses.

A soft, malleable, stable rare-earth element. Holmium laser systems are used in surgical procedures involving the cutting and vaporizing of soft tissue, cartilage and calcific structures.

Holmium lasers are a type of medical laser that utilizes holmium-doped crystals as the gain medium. The term holmium laser is often associated with a specific type of laser used in urology for...

A camera system used to form a high-precision hologram of the subject on a photographic plate. It contains a high-power pulsed laser as the illuminating source.

A multifaceted holographic disc that is rotated by a motor to deflect incident light to a scanning system's lens.

An interference pattern that is recorded on a high-resolution plate, the two interfering beams formed by a coherent beam from a laser and light scattered by an object. If after processing, the plate...

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 technique used to create a series of interrelated holographic images that give an appearance of motion when projected in sequence. A flashing laser is used in both the recording and projecting of...

The study of crystal growth from the molten stage utilizing a holographic system wherein interferometric techniques record detailed and measurable elements of crystal microstructure. In this way, the...

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,...

The three-dimensional interference pattern of fringes that is recorded on a holographic plate to facilitate the study of a complex object.

The interferometric analysis of a complex object by utilizing the three-dimensional hologram. By causing a laser beam to diverge into two directions, one of which directly strikes a holographic...

A photographic recording of interference patterns between a plane wave and a spherical wave on a high-resolution photographic emulsion.

A specific type of hologram that will transmit a pure plane wave when the hologram is illuminated by the type of wave it is matched to.

The storage of data as bits in memory by holographic processes. The laser beam is divided into reference and object beams, and bit information is stored as a hologram.

The holographic recording of a microscopic specimen whereby magnification is achieved by alteration in a wavelength or radius of curvature between recording and reconstruction of the wavefront. With...

The application of coherent wavefront techniques to the determination of the physical state of a system without appreciably altering that state.

A component used to modify light rays by diffraction; the HOE is produced by recording the interference pattern of two laser beams and can be used in place of lenses or prisms where diffraction...

A method of measuring flow velocity by seeding the flow with neutrally buoyant particles and using a pulsed laser to holographically record particle displacement during a short time period. An...

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...

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...

A series of permanent holograms in dichromated gelatin formed by opening total page-composer apertures and setting a point source of light in each storage location. It performs much like a...

With respect to a crystal, the characteristic of possessing two ends symmetrical with each other.

The perpendicular orientation of the molecular axes of the nematic molecules in a nematic crystal, relative to the electrode plates.

A term applied to rays that possess the same focal point, which may be infinity, thereby meaning that the rays are parallel.

A type of receiver utilizing a local oscillator phase-locked to the incoming signal.

That property of a substance that determines that all components of volume are the same in composition and optical properties.