Photonics Dictionary

1. An instrument used to determine the visual range in an environment. 2. A type of photometer that artificially reduces an object's visibility to threshold limits and records the quantity of...

Visual detection and ranging (ViDAR) is a technology that utilizes optical sensors, such as cameras or other imaging devices, to detect and track objects in the surrounding environment. Unlike...

A blank area (caused by insufficient inking of the paper) that falls within the range of an intended character stroke in an optical character-recognition system.

Volume Bragg gratings (VBGs) are specialized optical elements that consist of periodic variations in refractive index throughout the volume of a transparent material, typically a photosensitive glass...

Volumetric imaging refers to the capture, visualization, and analysis of three-dimensional (3D) information from a volume of space. Unlike traditional two-dimensional (2D) imaging, which provides...

A vortex phase plate is an optical device designed to impart a phase singularity, commonly referred to as a vortex or phase vortex, onto a light beam. This singularity results in a phase profile...

A system used for gratings that consists of a concave mirror, a grating and a plate holder mounted normal to the grating to reduce astigmatism and spherical aberration. The mounting yields a...

In the context of electronics and semiconductor manufacturing, a wafer refers to a thin, flat disk or substrate made of a semiconducting material, usually crystalline silicon. Wafers serve as the...

An image intensifier tube in which the photocathode and the output of the microchannel plate are proximity-focused on the microchannel plate input and output phosphor screen, respectively.

Also referred to as physical optics - the area of optics in which the wave nature of light is essential when defining its propagation. To exploit the wave phenomena of light, one must interact light...

An oscilloscope used to survey the waveform of a video signal.

A waveform is a graphical representation of the shape and magnitude of a signal over time. It typically depicts how the amplitude (strength) of the signal changes over time, with time plotted along...

A wavefront refers to the continuous surface or boundary representing points in a wave that are in phase, meaning they have the same phase or position in their respective cycles. In simpler terms,...

For each mode in an optical waveguide, the term used to describe the process by which an electromagnetic signal is distorted by virtue of the dependence of the phase and group velocities on...

A waveguide is a physical structure or device that is designed to confine and guide electromagnetic waves, such as radio waves, microwaves, or light waves. It is commonly used in communication...

A photofluorescent compound that, when used with a scintillating substance, absorbs photons and emits related photons having a greater wavelength. In this way a phototube or photocell may employ the...

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...

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...

The random noise having a spectral density that is substantially independent of the frequency over a specified frequency range. White noise is widely used in the random vibration testing of devices.

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...

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...

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...

The series of processes used to identify and evaluate crystal structure by using crystalline solids to diffract x-rays. In the Laue method, radiation of a wide range of wavelengths is transmitted by...

One of various types of fluorescent screens used to detect x-ray radiation. Photographic film is mildly sensitive to x-rays, but much more sensitive to light. Hence, in photographing x-ray...

A film or plate that is usually coated on both sides with a very fast emulsion that is sensitive to x-rays, and used to record x-ray diffraction patterns photographically.

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...

An instrument that is used to chart x-ray diffraction patterns, such as an x-ray spectrometer having photographic or other recording implements.

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

A rare gas used in small high-pressure arc lamps to produce a high-intensity source of light closely resembling the color quality of daylight.

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...

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.

Fluid used to aid in examination of semifinished blanks.

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,...

A ytterbium laser is a type of solid-state laser that employs ytterbium ions (Yb³+) as the dopant in the gain medium. These lasers are known for their high efficiency, broad absorption and...

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...

A type of semiconductor diode used in voltage-limiting circuits; when voltage reaches a certain value, the device becomes a conductor.

A telescope that is fixed or has a limited degree of movement in a vertical plane; primarily used to determine the position of stars near the zenith.

A highly flame-retardant material used to jacket fiber optic cables, especially on shipboard applications.

Zerodur is a type of glass ceramic material known for its exceptional thermal and mechanical properties, particularly its low coefficient of thermal expansion (CTE) close to zero. It was developed by...

A polycrystalline material that transmits in the infrared; it is used as a phosphor in x-ray and television screens.