Photonics Dictionary: L

A laser crystal, also known as an active medium or gain medium, is a solid-state material used in the construction of lasers. The primary function of the laser crystal is to amplify light by...

A group of single emitter laser diodes, usually arranged vertically or horizontally with respect to each other. The power output of the array increases in direct proportion to the number of single...

Laser lithotripsy is a medical procedure that uses laser energy to break down or fragment stones in various parts of the body, particularly in the urinary and biliary systems. The term "lithotripsy"...

A system that uses a continuous-wave laser to measure the velocity of an object by focusing the laser beam on the object, perpendicular to its direction of motion. An optical grating receives...

The photographic record of the diffracted beams formed when heterogeneous x-rays emerging from a pinhole or slit impinge upon one crystal.

The law stating that when light strikes a surface at such an angle that the reflected and refracted rays are perpendicular to each other, the maximum polarization of the light occurs in both...

The law stating that the angle of reflection is equal to the angle of incidence, the incident ray, reflected ray and normal to the surface, all being located in the same plane.

In an optical waveguide, a ray for which geometric optics would predict total internal reflection at the core boundary, but which suffers loss by virtue of the curved core boundary.

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.

A type of stereoscopic photography in which a pair of lenses focuses a pair of images, relative to the positions of the two eyes, onto film through a lenticular screen, which records the images as an...

The term light field refers to the spatial distribution of light rays traveling in all directions through a given space. It includes information about the intensity and direction of light rays at...

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 narrow cone of light rays that diverge from a point source or converge to an image point.

The path of a given point on a wavefront. One of the radii of a wave of light that indicates the direction of light travel.

Technique for measuring the volume bulk of materials as they move along a conveyor with an accuracy of better than 1 percent. Based on the use of high-resolution arrays of solid-state detectors, the...

Line scan refers to a method of capturing images or data by scanning a single line at a time, as opposed to capturing the entire image simultaneously. This technique is commonly used in various...

A line-scan camera, also known as a line-scan image sensor or linear array camera, is a type of digital camera designed to capture images one line or row of pixels at a time, rather than a full...

A solid-state video detector consisting of a single row of light-sensitive semiconductor devices, used in linear-array cameras.

A linear image sensor is a type of solid-state electronic device used to capture and convert light into electrical signals. Unlike area image sensors (such as CCD or CMOS sensors), which capture an...

Liquid crystal on silicon (LCoS) is a display technology that combines liquid crystal materials with silicon-based semiconductor technology to create high-resolution, high-quality images. LCoS...

The pattern, formed by a character generation cathode-ray tube system, in which the characters are made up of wave shapes synthesized by a series of sine and cosine terms.

A long-pass filter is an optical filter that allows longer wavelengths of light to pass through while blocking or attenuating shorter wavelengths. These filters are designed to transmit light with a...

The luminance portion of a composite video signal, i.e., the portion of the signal that corresponds to the brightness of the image apart from any color value, giving a monochrome, or gray scale,...

Fiber that emits luminescent radiation excited by ultraviolet, x-ray or high-energy particles.

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...