Photonics Dictionary: L

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.

A metal tool used to grind lenses with loose abrasive (see diamond cutting tool). The functional surface of the lap is carefully formed to be opposite the curve to be produced on the glass (concave...

An experimental research technique by which absorbed or unabsorbed radiation is analyzed in order to characterize and determine material properties, concentration as well as behavior under the...

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...

Area in which laser operation occurs and therefore safety requirements are met and regulations are implemented. Lasers operated within a laser controlled area may vary with energy and wavelength.

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...

The laser damage threshold refers to the maximum level of laser intensity that a material can withstand without experiencing damage. It is a critical parameter in laser applications and is...

Device that operates by interaction of incident radiation with semiconductor based material in order to produce an electrical signal or by other means, to interact with calorimetric devices which...

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 drift typically refers to a phenomenon where the frequency or wavelength of a laser source gradually changes over time. In the context of lasers, stability in terms of frequency or wavelength...

Usually consists of a set of filters that attenuate specific wavelengths but transmit as much visible radiation as possible.

A laser device intended for crushing urinary tract stones so they can be flushed from the body. Light is introduced via fiber optic delivery. A common wavelength used is 2.1 microns produced by...

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...

A fast-action shutter inserted between one end of a laser rod and the end mirror; when inserted to prevent emission and then quickly removed, it causes the laser to discharge suddenly with great...

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...

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 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...

A pump-probe technique whereby a single wavelength source may be used in order to excite a given sample to determine electronic transitions.

Laser-induced fluorescence (LIF) is a spectroscopic technique that involves using a laser to excite molecules or atoms, leading to their emission of fluorescence light. This technique is widely used...

The material that produces stimulated emission from within a laser oscillator. Laser gain media may vary from extended-length glass fibers to submicron-length semiconductor material.

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 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 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...

Defines the minimum operational standards for a self-sustaining fusion reactor as equivalence between energy released per volume unit and kinetic energy per unit volume.

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.

In the optical shop, the process of positioning and marking a blank or lens before surfacing, cutting and edging.

A thin-film photoconductive cell that is sensitive to the infrared region. The photosensitive material of the cell is composed of lead selenide, and the cell is used in the detection of infrared...

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...

A rotating disc that holds several lenses of differing focal length about a diameter. Used to switch lenses in a system while maintaining focus.

The production of rough glass lens blanks that are pressed while red-hot to the approximate size and shape of the finished lens, ready for fine grinding and polishing. Large companies often do their...

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...

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...

The ratio of the intensities of a light bundle before and after passing through the lens.

A lens is a transparent optical device that focuses or diverges light, allowing it to pass through and form an image. Lenses are commonly used in optical systems, such as cameras, telescopes,...

A hologram formed without lenses and with the object and reference points sharing the same plane. In the initial recording, each object point produces fringes having one spatial frequency across the...

Lensless microscopy, also known as computational or holographic microscopy, is an imaging technique that captures and reconstructs microscopic images without the use of traditional lenses. Instead of...

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...

A type of additive color photography using a lenticular structure impressed on a film base and a camera lens with a filter having three sectors of red, blue and green. Exposure of the film through...

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...

A device that serves to emit light of the same wavelength as the input light, only with an increase in intensity. It may be a solid-state device comprising photoconductive and luminescent layers...

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...

The term light field refers to the spatial distribution of light rays traveling in all directions through a given space. It includes information about the intensity and direction of light rays at...