Definitions: L

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...

Linear receive optics typically refers to the optical components and systems used in the reception (detection) of linearly polarized light signals in various applications, such as optical...

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

Linewidth, also known as spectral linewidth or line width, refers to a measure of the width of a frequency spectrum of a signal or a resonance. It indicates the range of frequencies over which the...

A Michelson-type interference microscope used to produce interference patterns of reflective specimens through the interference between light reflected by the specimen and that reflected by a...

A defect in the cleaved end face of an optical fiber, in the form of a sharp protrusion at the edge of the fiber.

A small half-shade analyzer placed in the eyepiece of a polarimeter to determine the character of the polarized light emitted by the instrument. It consists of a Nicol prism situated so that it...

A self-healing, index-matching, nonporous coating for optical components that can eliminate production difficulties and deficiencies associated with solid-film contamination and postdeposition...

Multimode straight fiber capable of transporting linearly polarized light with any incident polarization angle, and in which no form of internal stress can develop that could lead to birefringence.

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 solution or combination of solutions that serves as a filter.

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...

An optical fiber with a hollow core filled with a liquid material that has a higher refractive index than the solid surrounding it.

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....

A mirror composed of liquid, taking advantage of the parabolic shape of a spinning liquid and the fact that the mirror's focal length can be adjusted by altering the velocity at which the liquid's...

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...

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 crystal often used for windows and refracting components in the ultraviolet, visible and infrared. Characteristically, this form has excellent transmission from 0.14 to 6.0 µm.

A crystalline ferroelectric material used primarily as a substrate and an active medium for thin-film optical modulators and switches. It possesses very high electro-optic and piezoelectric...

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.

A mirror employed with a very high incidence angle to form a pair of coherent light sources by reflection, and therefore forming interference bands.

Data communications network in a clearly defined geographical location, and extending no more than a few miles in length. It generally takes in an office building or group of buildings, a campus or...

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 coherent optical communications systems, a laser used at the receiving end to produce a steady wave that is combined with the incoming laser signal before detection, generating a composite wave...

A lock-in amplifier is a specialized electronic instrument used to extract and measure small signals embedded in noise or interference. It is particularly useful in fields such as spectroscopy,...

One class of nonlinear space-invariant transformation processes used for processing convolved and multiplied signals.

A computer circuit that supplies the action of problem-solving functions or operations.

A diagram that uses special symbols called logic symbols to represent the detailed functioning of electronic logic circuits. The symbols do not represent the type of electronics used, but only their...

A fiber optic component or system designed in such a way that it can be operated by people without specialized knowledge of the field.

The partial differential equations for the spatial and time dependence of electric and magnetic fields inside a semiconductor. They are the analog of Maxwell's equations, which apply to the electric...

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 method that, by measuring the absorption along an atmospheric path at wavelengths ranging from two to a continuum, can determine pollution concentrations of gases.

Long-wave infrared (LWIR) refers to a specific range of the infrared spectrum. Infrared radiation is divided into three main categories based on wavelength: near-infrared (NIR), mid-wave infrared...

A filter that is transparent to longer wavelengths but opaque to shorter wavelengths.

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.

A waveform that can oscillate along the length of the laser cavity.

A dye laser cell configuration in which the dye flows in the direction of the axis of the laser, yielding symmetrical energy distribution but small repetition rates.

In image processing, the memory that stores the values for the point processes. Input pixel values are those for the original image, while output values are those displayed on the monitor as altered...

A form of mirage where objects near or just below the horizon appear in enlarged or distorted form because of atmospheric refraction. The glow in the sky caused by the presence of light below the...

In fiber optic cable, containment of the fiber or fibers within an outer protective tube in which they can move to some extent. The interstices usually are filled with an insulating material. See...