Photonics Dictionary

The magnetic flux that, linking a circuit of one turn, produces in it an electromotive force of one volt as it is reduced to zero at a uniform rate in one second.

A photometer that uses a wedge, marked to show its reduction of flux density, to make two light sources equal in intensity for comparison of luminous intensities. This is accomplished by the gradual...

A diffraction pattern sampling unit composed of a 32-element monolithic silicon photodiode array and a readout unit. The intensity on each detector element can be separately read out by means of a...

Also known as cathode-ray tube grid or shield. A cylindrically shaped electrode that, containing the cathode of a cathode-ray tube with opposite potential, is designed to focus and control the...

The Weissenberg method, named after the German physicist Karl Weissenberg, is a technique used in x-ray crystallography for obtaining high-quality diffraction patterns from single crystals. This...

A well plate, also known as a microplate or microtiter plate, is a flat plate with multiple small wells or depressions arranged in a grid pattern. Each well serves as a separate container for holding...

Whispering gallery mode (WGM) refers to a phenomenon in wave physics, particularly in optics, where waves, such as light or sound waves, are trapped and circulate along the periphery of a curved...

A feature of some imaging devices, such as digital cameras, that allows them to compensate for different lighting conditions by adjusting the color balance based on the difference between a white...

An extremely wide emission spectrum generated by the nonlinear effects created when a high peak power from a short-pulse laser is focused into a water or carbon tetrachloride cell. The resulting...

The use of whiteness formulas to replace visual assessment.

The theorem stating that, when the sampling period in a recorded sample hologram is matched to the object spectrum, the resulting image does not suffer any loss of information content.

Whole slide imaging (WSI), also known as virtual slide microscopy or digital pathology, is a technology that involves the digitalization of entire glass slides containing histological or cytological...

A wide-angle lens is a type of camera lens that has a shorter focal length than a standard or normal lens, allowing it to capture a broader field of view. Wide-angle lenses are characterized by their...

The formula that gives the wavelength of maximum spectral radiant emittance of a perfect blackbody: λmax = 2898/T(µm) The radiation at this λmax can be calculated as follows:...

A sealed, hard, magnetic disc drive used for the storage of data in a computer system.

1. A piece of glass with plane parallel surfaces used to admit light into an optical system and to exclude dirt and moisture. 2. A particular region of the electromagnetic spectrum that has been...

A technique for reducing data processing requirements by electronically defining only a small portion of the image to be analyzed, all other parts of it being ignored.

Specified curved optic intended for maximum collection of light, including off-axis rays, before leaving the exit aperture.

A type of radial gradient lens that can focus light even though its surfaces are flat.

Term for the brightness of an oscilloscope trace.

A Cassegrain telescope having a parabolic primary mirror, a spherical secondary mirror and a zero-power doublet in the converging bundle for aberration correction.

Radiography using the emission of x-rays to form an image of the structure penetrated by the radiation.

The bending of x-rays by the regular layers of molecules in a crystal acting like a very small diffraction grating. The diffraction pattern so obtained and recorded on film provides a means for...

An instrument that uses a crystal to diffract x-rays for the measurement of the intensities of the diffracted rays.

An image intensifier that consists of an evacuated tube with a large input phosphor screen at one end. The phosphor screen is in contact with a light-sensitive photocathode that emits electrons....

A method of projecting integrated circuit patterns on a silicon wafer using x-ray wavelengths focused through a special mask.

Used for high-resolution surface study with subnanometer resolution. XRIM uses interfacial phase contrast with application of hard x-rays over elementary surface structures availing the observation...

Also known as an anticathode. An electrode or electrode section that is focused upon by an electron beam and that emits x-rays.

The pressure in the gas region of an x-ray tube that has been reduced below 0.1 mm, the pressure necessary for the tube.

The arc formed when the rare gas xenon is excited electrically and emits a brilliant white light. Xenon is used to fill electronic and stroboscopic flashlamps, and also large discharge tubes for...

An instrument for eye surgery that directs intense xenon arc light through the transparent cornea lens to the retina where absorption by the pigment epithelium and the choroid produces heat and...

A high-intensity source of incoherent white light in which a capacitor is discharged through a tube of xenon gas; often used as a source of pumping radiation for various optically excited lasers.

A printing process of electrostatic electrophotography that uses a photoconductive insulating medium, in conjunction with infrared, visible or ultraviolet radiation, to produce latent...

A printing process of electrostatic electrophotography that uses a photoconductive insulating medium, in conjunction with x-rays or gamma rays, to produce latent electrostatic-charge patterns for...

Conventional coordinates for optical system analysis, the X-axis being the horizontal, the Y-axis the vertical and the Z-axis the optical axis of the system.

A YAG crystal refers to a solid-state crystal made of yttrium aluminum garnet (YAG), which is a synthetic crystalline material. YAG crystals are known for their exceptional optical properties,...

The constant equal to the unit stress divided by unit deformation, relative to all values and a substance's proportional restrictions.

The method by which Thomas Young in 1802 disproved Newton's corpuscular theory of light by the formation of interference patterns between two beams of light from the same source. This was produced by...

A technique for determining the nonlinear optical properties of a sample material by moving the sample through a focused laser beam and measuring changes in the beam's characteristics, such as...

The introduction of a filter into an imaging system to implement a phase contrast for an intensity mapping of a pure phase image.

A mirror that supplies equal reflectance for both the S-polarization and the P-polarization of a laser for a defined angle of incidence, usually 45°.

In a single-mode optical fiber, the wavelength that causes material dispersion and waveguide dispersion to cancel each other. In a multimode fiber, loose term for the wavelength at which there is a...

The removal of the zero-order component of the Fourier spectrum distribution of an object with a small, opaque absorber or reflector in the Fourier plane, to produce images that appear bright on a...

Schott Glass Technologies' trade name for a glass-ceramic material with a very low coefficient of thermal expansion.

A two-fiber optical cable containing two single-fiber cables that are connected by a strip of jacket and that can easily be separated from one another for the installation of optical connectors.

A small bulb containing a conducting gas, an arc being formed between a metal ring and a tiny zirconium electrode near the center of the ring. The heated zirconium emits light, and constitutes a...

An infrared transmitting material used in the production of fluoride glasses for optical fibers.