Photonics Dictionary: L

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...

Laser cooling is a technique used to reduce the temperature of a material or a collection of atoms or molecules by using laser light. It is based on the principle of selective absorption and emission...

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 laser rangefinder is a device that uses laser technology to measure the distance between the device and a target. It operates on the principle of measuring the time it takes for a laser beam to...

Sparkling granular pattern that is observed when an object diffusely reflects coincident laser light. Speckle appears as an irregularity in many holographs but has been exploited as a measurement...

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 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...

Laser viewing cards, also known as laser alignment cards or laser safety cards, are specialized cards or sheets designed to visualize laser beams or assist in aligning optical equipment while...

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...

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...

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...

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...

Lidar, short for light detection and ranging, is a remote sensing technology that uses laser light to measure distances and generate precise, three-dimensional information about the shape and...

Any device that is used to sense and measure light. See exposure meter; photoelectric exposure meter; photoelectric photometer; reflected light meter.

A handheld, light-sensitive device that is used with a display console to directly change, measure or erase the visual information presented. Interfaced with the computer that is generating the...

Technique for measuring the volume bulk of materials as they move along a conveyor with an accuracy of better than 1 percent. Based on the use of high-resolution arrays of solid-state detectors, the...

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.

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...

An objective measure of an object's brightness that is derived from the ratio of the luminance of its lightest section to that of its darkest section.

Luminosity refers to the total amount of energy emitted by an astronomical object, typically measured per unit time. It quantifies the intrinsic brightness of the object and is often expressed in...

Descriptive of the radiant power of visible light modified by the eye response. It is the measure of the flow of visible light energy past any given point in space in a given time period, and is...