Photonics Dictionary

Describing the standard television method of raster scanning in which the image is the product of two fields, each of which is a series of successively scanned lines separated by the equivalent of...

In an optical system with a series of lenses, images formed prior to the final focal plane.

The effect in which photons are absorbed and excite the electrons; the electrons move from the valence band to the conduction band (intrinsic photoeffect), from the valence band to impurity levels or...

A nonoptical surface, within lenses and lens mounts, that contributes largely to flare by reflecting light into the image space. As a result, such surfaces, so located, are finished with a dull...

The internet of things (IoT) refers to a network of interconnected physical devices, vehicles, appliances, and other objects embedded with sensors, actuators, software, and network connectivity....

A lens that is implanted within the eye to replace the eye lens, which has been removed because of cataract or other defect.

The absorption of a photon raising an electron across the forbidden gap from valence to conduction band of the semiconductor where conductivity is increased and incident radiation may be measured.

The rainbow exhibition of colors, usually caused by interference of light of different wavelengths reflected from superficial layers in the surface of a material.

A mechanical device designed to smoothly vary the effective diameter of a lens, thereby controlling the amount of light allowed through.

The adjustable membrane located just in front of the crystalline lens within the eye. The iris gives the eye its color. See also iris diaphragm.

A curve or surface having equivalent light intensity.

The slight difference in wavelength of an element's given spectral line observed in comparing different isotopes of that element.

A spectroscopic technique in which an excitation band absorbs laser energy resulting in an electronic transition. The isotopic species may then be measured using a time of flight mass spectrometer....

A small defocused Galilean telescope mounted in a hole in a door. Viewed from inside through the positive lens, a wide-angle view of the outside is seen; viewed from outside through the negative...

An eyepiece consisting of a planoconvex field lens and a cemented doublet as the eye lens.

An atmospheric nonlinear process unique to CO2 laser wavelengths, whereby CO2 absorbs 10.6-µm radiation and the CO2 molecules in the (100) vibrational state are excited to the (001) level, and...

Lens which, by altering the phase, efficiently images through a holographic process.

For any point on a thermal radiator, at thermal equilibrium and for each wavelength, the emissivity in any direction is equal to the absorptance for radiation from the same direction.

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.

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