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...

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...

An artificial star used to aid in adaptive optics imaging of the sky. The guide star is provided from a telescope system on the ground and is directed into the imaged region. The wavefront...

The study concerned with the stimulation of chemical activity by laser light as a result of the absorption of photons by a molecule. Interaction of laser source with a molecular or atomic species....

In hybrid or monolithic integrated circuits, the laser ablation of a portion of resistor material to achieve the design resistance value of the circuit.

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,...

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...

A stroboscopelike apparatus that uses a copper vapor laser to illuminate an object for very short time periods (about 30 ns).

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...

A length that denotes the size of the unit cell in a crystal lattice. With respect to the cubic crystal, this is the length of the side of the unit cell. However, a simple definition of the term is...

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 circle of confusion is a defocused or aberrated image of a point. Focus is generally set where the diameter of this circle is minimized or least.

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...

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.

A term for thermoplastic optical materials; that is, those in which the polymer chains remain linear after heating and molding and which thus can be remolded again and again, unlike thermoset...

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...

Liquid crystals are a state of matter that exhibits properties intermediate between those of conventional liquids and solid crystals. In a liquid crystal, the molecules are ordered like those in a...

An alphanumeric display formed by a layer of liquid crystal material sandwiched between two sheets of glass; a transparent conductive coating on the glass is etched to form the character segments. An...

A wireless stereo imaging device used in conjunction with a monitor to produce a virtual interactive environment. Liquid crystal shutters in the eyewear are synchronized with the monitor at 120...

A liquid crystal light valve (LCLV), also known as a spatial light modulator (SLM), is an optical device that modulates the intensity, phase, or polarization of light passing through it using liquid...

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...

A device used to evaluate the quality of fiber optic splices made in the field by injecting light into the cladding of the fiber and measuring the output at the other end of the splice.

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

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

A physical stop that is conjugate to the entrance pupil and is used primarily to reduce diffraction effects at longer wavelengths.

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 laser, which stands for "light amplification by stimulated emission of radiation," is a device that produces coherent and focused beams of light through the process of optical amplification based...

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...

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.

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...

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

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...

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 broken circle used as the test object in distinguishing visual acuity. The width of the gap in the circle is equal to the breadth of the black line and one-fifth the circle diameter. Also known as...

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...

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

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...

Optical fiber with a large core, often a step-index fiber; "large'' is at times defined as greater than 85 µm.

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 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...

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...