Photonics Dictionary

Attosecond-pump attosecond-probe spectroscopy (APAP) is an advanced technique in ultrafast spectroscopy that allows scientists to study the dynamics of electronic processes occurring on extremely...

An autocollimator is an optical instrument used for measuring small angular deviations with high precision. It operates on the principle of autocollimation, where a light source is directed onto a...

1. A bundle of light rays that may be parallel, converging or diverging. 2. A concentrated, unidirectional stream of particles. 3. A concentrated, unidirectional flow of electromagnetic waves.

A parallel plate of glass in such a position that the refracted and reflected rays of incident parallel light are mutually perpendicular. In this situation the reflected light is plane polarized, and...

A fiber optic end plate constructed by drawing a bundle of parallel fibers embedded in glass and cutting it into thin slices. These slices are assembled in a plane and heated to produce a...

Radiation in which every ray from any given object point can be considered to be parallel to every other. This is never completely the case: The light from a star is really diverging, and all...

Concave is an adjective used to describe a surface or shape that curves inward or has a hollow or recessed appearance. In the context of geometry or optics, a concave shape is one that curves or...

Concave and convex spherical mirrors are types of curved mirrors that have surfaces shaped like segments of spheres. These mirrors are commonly used in optics for various applications, including...

Convex is an adjective used to describe a surface or shape that curves outward, bulges, or has a rounded and outwardly extending appearance. In the context of geometry or optics, a convex shape is...

A Dammann grating is a type of diffractive optical element (DOE) used to create an array of equally spaced, uniform-intensity spots or beams. It is named after its inventor, Dr. Herbert Dammann. The...

A diffraction grating is an optical component consisting of a surface with a periodic structure of equally spaced, parallel grooves or rulings. These rulings act as an array of closely spaced slits...

A laser having a rod that is a stacked array of discs immersed in a transparent flowing coolant fluid. In this way, the cooling rate is increased, the temperature gradients are basically parallel to...

A diverging lens is a type of lens that causes parallel rays of light to spread out or diverge. It is thinner in the center than at the edges and is commonly referred to as a concave lens. The most...

A form of prism invented by H.W. Dove. It resembles half of a common right-angle prism in which a ray entering parallel to the hypotenuse face is reflected internally at that face and emerges...

The focal length of a lens is the distance between the lens's optical center (or principal point) and the image sensor or film when the lens is focused at infinity. In simple terms, it is the...

That point on the optical axis of a lens, to which an incident bundle of parallel light rays will converge.

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

A lens is a transparent optical device that focuses or diverges light, allowing it to pass through and form an image. Lenses are commonly used in optical systems, such as cameras, telescopes,...

An array or mosaic of optical surfaces. May be a number of lenses closely packed to form multiple images or many parallel cylinders used as a projection screen.

In optics, a pattern, such as the Buchmann-Meyer pattern, that may be viewed when the record surface is illuminated by a light beam having parallel rays.

A dielectric sphere with an index of refraction that varies with distance from the sphere center. A parallel beam of rays is focused on the lens surface at a point diametrically opposite the...

The point on the optical axis of a lens that is the image of the nodal points. For any bundle of rays passing through the optical center of a lens, the incident and emergent rays through this point...

A transparent crystalline substance in which the refractive index of the optic axis (extraordinary axis) is different from the other two crystal axes. Two polarization directions are allowed for any...

A concave mirror that has the form of a paraboloid of revolution. The paraboloidal mirror may have only a portion of a paraboloidal surface through which the axis does not pass, and is known as an...

Parallel scanning refers to a method of acquiring data or images simultaneously from multiple sources or in parallel, rather than sequentially scanning each source one after another. This approach is...

In a camera or cathode-ray tube, distortion that is designated by a lateral skewing of the reproduced image.

A ray that behaves according to paraxial equations; one that lies close to and almost parallel to the optical axis.

A form of dispersing prism, often used in monochromators, that consists of a common right-angle prism with a 30° dispersing prism attached to each of its square faces. The spectrum formed by the...

A Peltier cooler, also known as a thermoelectric cooler (TEC) or thermoelectric module, is a solid-state device that uses the Peltier effect to transfer heat between two electrical junctions. It can...

The chromatic resolving power of a prism is invariably stated for the case in which parallel rays of light are incident on the prism, in which the prism is oriented at the angle of minimum deviation...

A measure of an optical system's ability to produce an image which separates two points or parallel lines on the object. See Rayleigh criterion of resolving power.

Seidel aberrations refer to a set of monochromatic aberrations in optical systems, named after the German mathematician and physicist Ludwig von Seidel. These aberrations describe deviations from...

A variation of tomography, which is a means of visualizing any one of a large set of parallel planes in the patient. A series of x-ray pictures taken from different angles results in developed...

A spheric lens, also known as a spherical lens, is a type of optical lens with at least one surface that is part of a sphere. This means that the lens surface is curved in a symmetrical manner,...