Photonics Dictionary: L

A perfectly diffusing surface; the intensity of the light emanating in a given direction from any small surface component is proportional to the cosine of the angle of the normal to the surface. The...

The acoustical holographic process in which the hologram consists of slight elevations in a liquid surface, in the areas of the antinodes of the interference pattern. Light diffracted from this...

Label-free refers to a technique or method that does not require the use of additional labels, tags, or markers to detect or identify specific components or entities. In various scientific and...

Flux per unit solid angle leaving a surface in any direction is proportional to the cosine of the angle between that direction and the normal to the surface. A material that obeys Lambert's cosine...

A method of depositing crystalline films one molecular layer at a time, by dipping the substrate into water containing a polymer that forms a single layer of molecular chains on the surface. This...

A metal tool used to grind lenses with loose abrasive (see diamond cutting tool). The functional surface of the lap is carefully formed to be opposite the curve to be produced on the glass (concave...

1. The process of wearing down the surface of a softer material by rubbing it under pressure against the surface of a harder material that has been formed in the shape opposite to that desired on the...

Laser ablation is a process that involves the removal or erosion of material from a target surface using laser energy. This technique is widely used in various scientific, industrial, and medical...

Laser annealing is a process that involves using a laser beam to heat and modify the microstructure of a material, typically a thin film or surface layer, with the objective of improving its...

A natural or mechanical system adversely affected by the influence of laser radiation. During laser damage the common effect of the radiation on the surface of interest is heat accumulation due to...

High power laser ablation device that by pulsed operation produces holes of controllable dimension on the scale of microns. Laser drill applications include turbine manufacturing and surface metal...

Laser marking is a process in which a laser beam is used to mark or engrave a surface by altering its properties or appearance. This technique is widely used for labeling, identification, and...

Laser peening is a surface enhancement technique used to improve the mechanical properties of materials, particularly metals. It involves the use of high-energy laser pulses to generate shockwaves on...

A plasma produced by the interaction of an intense laser pulse with a material surface. Production of ionized particle with high intensity radiation. The narrow path of the intense field produces a...

A nondestructive test, also referred to as LASAT, that uses a high-energy laser pulse that is targeted on an adhesively bonded part, resulting in the formation of plasma on its surface and,...

Laser texturing is a manufacturing process that involves using a laser beam to selectively modify the surface of a material, creating textures, patterns, or microstructures. This technique is...

A lateral shearing interferometer is an optical device used in interferometry to measure phase differences between two beams of light. Interferometry is a technique that combines and analyzes...

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.

The process of removing some of the constituents of a glass surface by chemical action.

In a sequence of laser pulse emissions, the intitial pulse that often helps initiate a reaction at the target surface, whereas the trailing edge maintains the reaction.

A lens blank is a piece of optical material in a raw, unfinished state, typically in the form of a disk or block, from which lenses are eventually fabricated. Lens blanks are made from various...

A tool used to determine the curvature of a lens surface in terms of dioptric power. See lens watch; spherometer.

A line passing through the center of a lens surface, from edge to edge.

Lens testing equipment refers to a range of specialized tools and instruments used to evaluate the optical performance, quality, and characteristics of lenses. These instruments are essential for...

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 rear or front projection screen composed of minute optical surfaces that introduce a spread to the light beam that conforms approximately to the light distribution requirements of the application.

Lidar, short for light detection and ranging, is a remote sensing technology that uses laser light to measure distances and generate precise, three-dimensional information about the shape and...

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 mappable surface feature arranged in straight or curved lines that is distinguished from surrounding surfaces and is formed as a result of the landform's internal characteristics.

A linear positioning stage, also known as a linear stage or translation stage, is a precision mechanical device used to accurately move and position objects along a linear axis. These stages are...

Subsurface linear arrangement of elements of rock that is not mappable; lineation is a one-dimensional characteristic.

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...

An immersion liquid used to treat polarizing filters to eliminate the effects of surface variations and to minimize the optical path difference between that part of the spectrum that passes through...

Liquid marble refers to a unique form of microscale liquid encapsulation, where small droplets of liquid are coated with a fine layer of hydrophobic powder, such as silica nanoparticles or Teflon....

Lithography is a key process used in microfabrication and semiconductor manufacturing to create intricate patterns on the surface of substrates, typically silicon wafers. It involves the transfer of...

A 30-60-90° spectrograph prism that is coated on the surface opposite the 60° angle with a reflecting film.

A spectrograph using a prism that has an internally reflecting surface and that serves as a constant deviation prism.

Term used to describe an optical surface that contacts the test glass only at its edges.

Low Earth orbit (LEO) refers to a region in space that is relatively close to Earth's surface, typically characterized by altitudes ranging from approximately 180 to 2,000 kilometers (112 to 1,242...

Luminous flux emitted from a surface per unit solid angle per unit of area, projected onto a plane normal to the direction of propagation. Also known as brightness and luminous sterance.

The total luminous flux given out per unit area; i.e., the sum of the luminous emittance and any radiation that is reflected from and/or transmitted through the surface: expressed as lumens per area.

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...