Photonics Dictionary: L

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...

The force acting upon a charged particle as it moves in a magnetic field, proportional to the particle's charge and velocity.

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...

The total optical power loss in a system. The loss budget is often stated in terms of the transmitted power and the power required at the receiver to express the maximum acceptable amount of loss.

A medium that scatters or absorbs radiation that passes through it.

A low-power (2x to 10x) magnifier consisting of a single positive lens assembly.

A subtractive colorimeter that expresses a liquid's or object's color as a combination of three colors. These colors are developed through viewing the specimen object through three series of slides,...

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...

An interference microscope that uses a light beam originating from a low-coherence light source. The sample is placed in one interferometer arm, and the other arm provides a reference beam. The...

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

Optical fiber that transmits a greater percentage of input light than does high-loss step-index fiber. Low-loss fiber requires higher purity materials and a more sophisticated drawing process and...

In digital image processing, a method of convolution that reduces random noise by replacing the value of each pixel with the average of that pixel plus its neighbors, or of the neighbors alone. Also...

The analysis of structural and molecular dynamics caused by low temperature.

The luminance portion of a composite video signal, i.e., the portion of the signal that corresponds to the brightness of the image apart from any color value, giving a monochrome, or gray scale,...

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...

SI unit of quantity of light.

A laser effect used especially for laser light shows. Lumia are created by placing a distorting medium such as rippled glass in the path of the laser beam.