Photonics Dictionary

Vibrational spectroscopy is a type of spectroscopy that involves the study of the vibrational states of molecules. It is used to obtain information about the molecular structure, bonding, and...

A vibrational transition refers to a change in the vibrational energy of a molecule. Molecules consist of atoms that are connected by chemical bonds, and these atoms are not stationary but are in...

Videography refers to the process of capturing moving images and recording them in a digital format. It involves the use of video cameras, lighting equipment, and audio recording devices to create...

A small television tube originally developed for closed-circuit television. It is about 1 inch in diameter and 5 inches long. Its controls are relatively simple and can be operated by unskilled...

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...

Vision transformer (ViT) networks are neural network architectures that apply the Transformer architecture, originally developed for natural language processing, to the task of processing visual...

A pair of stars (double star) that can be seen separately with a telescope, generally by setting a filar micrometer for the separation and position angle. Observation of visual binaries improves with...

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...

The induced birefringence in isotropic gases that results when the gases are placed in strong fields.

A nondestructive testing method for very large scale integration circuits, using a scanning electron microscope to monitor changes in the electronic state of the chip as it is fed test voltages while...

A device that converts alternating voltage to direct voltage, while at the same time increasing its amplitude.

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...

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 device that consists of two types of mode converters, one of which must be magnetic. It is nonreciprocal because the coupling constants of the two mode converters have a different phase relation...

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...

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.

An optical filter so constructed that the density increases progressively from one end to the other, or angularly around a circular disc.

An optical element having plane-inclined surfaces. Usually the faces are inclined toward one another at very small angles. Wedges divert light toward their thicker portions, and may be circular,...

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 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...

After putting a thick photographic emulsion on a front-faced mirror, and exposing the emulsion to monochromatic incident light normal to the face, Wiener discovered, upon developing the emulsion,...

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.

In micropositioning systems, motion (most frequently undesired) about the Z-axis.

A polarizing prism consisting of two calcite prisms cemented such that they deviate the two emerging beams (which are mutually perpendicularly polarized) by nearly equal amounts in opposite...

A grazing incidence mirror telescope with concentric conic surfaces having a single common point: a paraboloid-hyperboloid combination with two internal reflections.

In microscopy, the clear distance between the specimen being viewed and the first optical element of the objective lens.

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

X resolution is a measure of the number of pixels or data points along the horizontal axis of an image or display. It quantifies the level of detail that can be displayed horizontally, representing...

1. In a plane Cartesian coordinate system, the horizontal axis, or axis in the left to right direction. 2. In a quartz crystal structure, the refrence axis.

The collection and detection of x-rays by virtue of their ionizing properties. The ionization may be perceived directly by a gas-filled ionization chamber, photographically, or by correlating...

Irradiation of a cylindrical crystal with an x-ray beam resulting in Bragg diffraction that produces a slightly enlarged image.

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

The method of acquiring characteristic x-ray spectra from microscopic samples by use of the combination of a scanning electron microscope and x-ray spectroscopy.