Photonics Dictionary: L

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...

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 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 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...

A laser diode module is a compact device that incorporates a laser diode, optics, and often other components into a single package. These modules are designed to provide a convenient and efficient...

Laser optics refers to a broad category of optical components and systems designed for manipulating and controlling laser light. Laser optics play a crucial role in shaping the characteristics of...

The laser output refers to the generated and emitted light produced by a laser system. This output is characterized by several key properties that distinguish lasers from other light sources. These...

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....

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...

Laser surgery refers to a medical procedure in which a laser, or focused beam of light, is used as a precision tool to cut, vaporize, coagulate, or otherwise modify tissues for therapeutic or...

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...

Lens aberration resulting in image size variation as a function of wavelength. See also chromatic aberration.

In photonics, a lattice refers to a periodic arrangement of optical elements or structures, often on a microscopic or nanoscopic scale. These optical lattices can be created using various techniques...

In a fiber optic cable, the longitudinal length required for the transmission media, wrapped around a central member, to complete one helical wrap. Also called pitch.

A lens blank is a piece of optical material in a raw, unfinished state, typically in the form of a disk or block, from which lenses are eventually fabricated. Lens blanks are made from various...

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

The metal tube that maintains the optical components of a lens in proper relationship. Some lenses are mounted in metal cells, which in turn are screwed to the front and rear of a shutter or lens...

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...

Electromagnetic radiation detectable by the eye, ranging in wavelength from about 400 to 750 nm. In photonic applications light can be considered to cover the nonvisible portion of the spectrum which...

Light diffusion refers to the process by which light is scattered or spread out in various directions as it interacts with a medium or material. Unlike direct transmission through a transparent...

The process whereby white light is separated into its component wavelengths. Light beams of different wavelengths are separated from each other by undergoing a different angular deviation. Prisms and...

Phenomenon caused by an ultrashort and ultra-intense light pulse propagating in a Kerr medium, such as air or water. When the pulse's power exceeds the critical power (approximately 3 GW in air),...

An LED, or light emitting diode, is a semiconductor device that emits light when an electric current passes through it. LEDs are widely used in various applications due to their energy efficiency,...

A linear image sensor is a type of solid-state electronic device used to capture and convert light into electrical signals. Unlike area image sensors (such as CCD or CMOS sensors), which capture an...

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...

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...

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 30-60-90° spectrograph prism that is coated on the surface opposite the 60° angle with a reflecting film.

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

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,...

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...

Luminescence is the emission of light that occurs without the involved substance undergoing a significant increase in temperature. In other words, it is the production and emission of light by a...

A collector for photovoltaic power generation that consists of a thin plate that strongly absorbs sunlight striking its faces and luminesces efficiently. A large fraction of the luminescence is...

A dielectric sphere with an index of refraction that varies with distance from the sphere center. A parallel beam of rays is focused on the lens surface at a point diametrically opposite the...