Photonics Dictionary: L

An optical source that has a luminous distribution that is uniform for all directions.

Composed of layers.

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 device used for measuring the height of clouds from a position on the ground. Measurement technique uses a vertically directed beam stably positioned such that scattered radiation may be detected...

Visible laser radiation, often optically expanded and collimated, used to induced temporary blindness from within a walking distance of an impending target. Laser dazzle systems may be in a handheld...

Device that operates by interaction of incident radiation with semiconductor based material in order to produce an electrical signal or by other means, to interact with calorimetric devices which...

Device which determines particle velocity through the measurement of scattered interference of a beam pair from a single source. The measured light is Doppler shifted which provides information...

Means of determining the relative motion of a (seismic) mass or acceleration body from a stable laser operated system.

An interferometer that uses a laser as its light source. The purely monochromatic nature of the laser results in improved efficiency and overall performance.

A narrow linewidth optically transmissive or reflective component intended for use with a highly monochromatic or single mode source.

A laser device intended for crushing urinary tract stones so they can be flushed from the body. Light is introduced via fiber optic delivery. A common wavelength used is 2.1 microns produced by...

Laser materials processing refers to a diverse set of manufacturing techniques that utilize lasers to modify, cut, weld, drill, or otherwise manipulate materials. These techniques offer high...

Laser parameters are the characteristics that define the behavior and performance of a laser. These parameters can be categorized into several groups: spatial, temporal, spectral, and operational. ...

Production of a repeated image of a transmitted beam through a diffractive optical element such as a holographic card or component disk. Creating moving or stationary optical designs via a system of...

Handheld optical laser device containing a semiconductor or DPSS source. The output is corrected via internal collimating optics. For typical use the output is reduced to eyesafe operation power. (5...

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 sintering is an additive manufacturing (AM) or 3D printing technology that involves using a laser to selectively fuse powdered materials, typically polymers or metals, layer by layer, to create...

An instrument usually consisting of a very long interferometer, 3 to 800 m, and a laser light source for the study and measurement of strain, such as those formed by earth tides and gravitational...

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 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 variation of the electronically detected signal with respect to the scaled version of the classical optical signal incident on the photomultiplier tube.

A type of fluorescence spectroscopy in which an excimer laser, a dye laser and a frequency-doubling device are used to detect polycyclic hydrocarbon atoms to a part-per-billion level.

A scattering photometer using scattered light in the solid angle 4.51+0 19° with respect to the forward direction, and an impactor with a rectangular jet. Scattered light intensities of entering...

Laser-mediated gene transfer refers to a technique in molecular biology and genetic engineering that utilizes lasers to introduce genetic material into cells. This method is a type of gene delivery...

Latency is the time interval between the stimulation or input of a system and the response or output. It is a measure of the time delay experienced in a system, network, or process. Latency can occur...

A short term for latent image intensification, a process much like hypersensitizing in photography, but used after exposure and before development of the negative.

The pattern of physical or chemical changes that has taken place in a photographic emulsion, by its exposure to light, that will form a visible image when the emulsion is developed. Also known as...

Lens aberration resulting in image size variation as a function of wavelength. See also chromatic aberration.

A set of photodiodes with no gaps between them that can sense the displacement of a spot of light anywhere on the sensing area.

An extensometer used to measure deformations in the thickness of a plate caused by tension, compression or other stress.

A method of measuring microbending losses in optical fiber by sandwiching a length of fiber between two parallel plates, with 150-grit sandpaper on the bottom plate. Different weights are placed on...

In a diode laser, a mode in the plane of the active layer that is perpendicular to the direction of the emitted beam.

A power loss caused by transverse or lateral deviation from optimum alignment of source to optical waveguide, waveguide to waveguide, or waveguide to detector.

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 perception of visual stimuli at the left and right outer boundaries of the visual field.

Light generated along the interface when light is incident in the neighborhood of the total internal reflection angle.

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

A Laurent polarimeter is an instrument used in optics for measuring the rotation of plane-polarized light caused by optically active substances. Optical rotation, also known as optical activity, is a...

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...

Defines the minimum operational standards for a self-sustaining fusion reactor as equivalence between energy released per volume unit and kinetic energy per unit volume.

A ferroelectric polycrystalline ceramic material used in optical memories for computers and as a piezoelectric transducer.

Two or more lenses arranged to act in conjunction with one another.

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 ophthalmic instrument used to measure the magnitude and direction of the maximum and minimum powers of a spectacle lens, and mark the optical center of the lens by an ink dot. When the lens to be...

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 stereo image that is recorded by the lenticular, stereo photographic process.

Leukocytes, commonly known as white blood cells, are a crucial component of the immune system in vertebrates, including humans. These cells are responsible for defending the body against infections...

A homogeneous optical medium or coating that transmits only in particular regions of the spectrum. It is used to change or modify the total or relative energy distribution of a beam of light.