Photonics Dictionary

The study of the physics of x-rays, where the x-rays exhibit properties similar to those of lightwaves. Also called Roentgen optics.

Ray oriented and assumed to propagate orthogonal to the optical axis

An angle formed by the lines of sight of both eyes when focusing on an object. Also, the rate at which a ray approaches the optical axis.

An APD detector, or avalanche photodiode detector, is a type of photodetector used to detect light or optical signals by converting incoming photons into electrical current. It operates based on the...

Aplanatic points refer to specific points in an optical system where certain aberrations, such as spherical aberration or coma, are minimized or eliminated. In an optical system, aberrations are...

An aplanatic surface is an optical surface that is specifically designed or shaped to minimize spherical aberration and coma. Spherical aberration is an optical aberration that occurs when light rays...

Attenuation refers to the gradual loss or reduction of intensity, force, or magnitude of a particular property as it propagates through a medium or travels over a distance. This concept is prevalent...

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...

A bundle of rays that originates from an object point on the optical axis of a lens system.

A paraxial light ray that extends from an object point on the optical axis.

1. A geometrical arrangement of two or more light beams for use in laser shows, object detection or other applications requiring arrayed multiple beams. 2. A mathematical 2 X 2 or 3 X 3 matrix for...

Birefringence is an optical property of certain materials that causes them to exhibit different refractive indices for light of different polarizations. In other words, when light passes through a...

A blue diode laser is a type of semiconductor laser that emits light in the blue wavelength range of the electromagnetic spectrum, typically between 400 and 500 nanometers. Diode lasers are compact,...

A CCD image sensor, or charge-coupled device image sensor, is a type of electronic device used to convert optical images into electronic signals. It is a key component in digital cameras, camcorders,...

The ray that passes through the center of the aperture stop in an optical system. It often is called the principal ray of an oblique beam.

A mode that is confined by virtue of a lower-index medium surrounding the cladding. Cladding modes, in the terminology of mode descriptors, are equivalent to cladding rays in the terminology of...

A coherent fiber bundle (CFB), also known as a coherent fiber optic bundle, is an assembly of multiple optical fibers arranged in a specific geometric pattern to maintain the spatial coherence of...

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...

1. In optics, the bending of light rays toward each other, as by a convex or positive lens. 2. Turning in the eyes to view a near object. 3. In a television picture tube, the crossing of the...

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 cylindrical lens is an optical component that has different curvatures along its two orthogonal axes, resulting in a shape resembling a cylinder. Unlike spherical lenses, which have the same...

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...

1. In optics, the bending of rays away from each other. 2. In lasers, the spreading of a laser beam with increased distance from the exit aperture. Also called beam spread. 3. In a binocular...

The separation of unpolarized light into two plane-polarized elements by a doubly refracting crystal. When a crystal, such as calcite, is placed between the eye and a pinhole in a card, two bright...

The angle between a light ray emerging from an optical system and the optical axis of that system.

A fiber optic spectrometer is a device used for measuring the spectral content of light. It utilizes optical fibers to transmit light from a source to a spectrometer unit, where the light is...

The field of view (FOV) refers to the extent of the observable world or the visible area that can be seen at any given moment through a device, such as an optical instrument, camera, or sensor. It is...

Fluence is a term used in various scientific and technical disciplines to describe the amount of something per unit area. The specific meaning of fluence can vary depending on the context in which it...

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 Fresnel lens is a type of optical lens that consists of a series of concentric grooves or steps carved into a flat, thin piece of transparent material, typically plastic or glass. This design...

A GaAlAs laser is a type of semiconductor laser diode that emits light in the near-infrared region of the electromagnetic spectrum. It is composed of layers of gallium, aluminum, and arsenic, hence...

GaN (gallium nitride) distributed feedback (DFB) lasers refer to a specific type of semiconductor laser based on Gallium Nitride materials and designed with a distributed feedback structure. These...

A field of physics that deals with light as if it truly were composed of rays diverging in various directions from the source and abruptly bent by refraction or turned by reflection into paths...

A GRIN (gradient index) lens is a type of optical lens that utilizes a gradient in refractive index across its volume rather than having a uniform refractive index like conventional lenses. This...

An optical system that superimposes a synthetic display providing navigational or weapon-aiming information on a pilot's or driver's field of view. The system includes a cathode-ray tube, collimating...

High harmonic generation (HHG) refers to a nonlinear optical process in which intense laser light interacts with a gaseous medium, typically an atom or a molecule, to produce harmonics of the...

A hyperspectral imaging camera is a sophisticated imaging device capable of capturing and processing data across a wide range of wavelengths within the electromagnetic spectrum, typically from...

Also referred to as image visibility, the contrast of an image is the variation in the intensity of an image formed by an optical system, where the image pixels are defined on a gray scale scheme of...

A measure of the closeness with which an optical image is capable of resembling the original object. The factors that affect image quality are lens aberrations, diffraction, dirt and stray light...

An infrared camera, also known as a thermal imaging camera or IR camera, is a device that captures and visualizes the infrared radiation emitted by objects, revealing temperature variations across...

An impurity-doped silicon detector array sensitive to long infrared wavelengths, installed in optical collecting systems capable of detecting the presence of infrared-emitting objects at extensive...

An optical system used to collect infrared energy from a scene using scanning optics with a point or line detector, as compared with a fixed optical system with a full two-dimensional detector array.