Photonics Dictionary: L

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...

A grating with ridges of rectangular cross section, generally equal in width to the space between. This type of grating may be used as a beam divider.

Laser active elements typically refers to the substances or materials within a laser system that play a critical role in the amplification of light through the process of stimulated emission. These...

A moving group of fluid-suspended biological species directed through separate channels by which the population is isolated. The isolated or purified group is observed by applying a laser detection...

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...

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 system that uses the heat from a pulsed laser to weld metals. Because of the rapidity and localization in which the welding takes place, metals of vastly dissimilar melting points can be welded...

A contact tip made of artificial sapphire (AlO2) that allows surgeons to use laser power to cut and coagulate tissue simultaneously.

A thin-film photoconductive cell that is sensitive to the infrared region. The photosensitive material of the cell is composed of lead selenide, and the cell is used in the detection of infrared...

A photoconductive cell having greatest sensitivity in the infrared region. The photosensitive material of the cell is lead sulfide, which is deposited on a glass plate.

The mechanical structure that holds a number of individual lens elements.

One optical element of a multielement lens. See optical element.

LiFi, short for light fidelity, is a wireless communication technology that utilizes visible light or infrared light to transmit data. Developed as an alternative or complementary technology to...

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...

Technology that relies on a highly efficient photodetector that can detect incoming light signals at one frequency and transmit outgoing signals at another, thus permitting the sending and receiving...

A device used to accelerate the electrons in a free-electron laser. There are several types, including the induction linear accelerator, the radio frequency linear accelerator and the superconducting...

A device for which the output electric field is linearly proportional to the input electric field, and no new wavelengths or modulation frequencies are generated.

The measured width of the field of view at any distance.

In fiber optic communications systems, generally one that operates between 1000 and 1700 nm.

Pockels cell or dynamic optical retarder in which the electrical field is applied in a direction parallel to that of light passing through it.

The Lorentz oscillator model is a theoretical model used in physics to describe the response of a charged particle (such as an electron) to an oscillating electric field. It is particularly employed...

Instrumentation designed to permit the perception, recording or measurement of scenes under conditions of low incident illumination.

A lumen is a unit of measurement used to quantify the amount of luminous flux, which is the perceived power of light. In other words, the lumen measures the total amount of visible light emitted by a...

A lab-on-a-chip (LOC) is a miniaturized device that integrates various laboratory functions and capabilities onto a single, compact chip. Also known as microfluidic devices, lab-on-a-chip systems are...

A diagram that shows actual component signals and the basic wiring configuration of a relay logic circuit.

A term applied to an electric charge image in a camera tube that remains for a period of a few frames after its initial formation.

Term for service offered by a vendor who leases a particular wavelength to a customer through DWDM technology. Lambda services are often associated with the leasing of dark fiber.

A unit of luminance equal to 1/p candela per square centimeter. (l).

A dark band that may appear in the field of crossed Nicol prisms with a powerful source such as the sun because the light is not strictly parallel and is not extinguished immediately.

A nonluminous area around a negatively charged probe that is inserted into the positive column of an arc or glow discharge.

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...

An endoscopic surgical instrument that includes a channel for the introduction of supplementary instruments.

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...

An experimental research technique by which absorbed or unabsorbed radiation is analyzed in order to characterize and determine material properties, concentration as well as behavior under the...

The process by which laser emission is used in measuring fluid velocity and, more specifically, the detection of air and wind velocity.The laser technique measures the amount of frequency shift...

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 laser cavity, also known as an optical cavity or resonator, is a fundamental component of a laser system. It is a confined region or space where light undergoes multiple reflections, leading to the...

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...

A scanning laser radar system applied to transmission and concentration analysis in three dimensions of clouds as well as aerosols and other particles within atmospheric systems.

A surgical device used to deliver laser light. Specifically,contact tips are made with artificially grown sapphire which is precisely cut to an orientation which permits efficient light transmission....