Photonics Dictionary

An optical table, also known as an optical bench or an optical breadboard, is a specialized platform used in optics laboratories for mounting and aligning optical components. These tables provide a...

3D printing, also known as additive manufacturing (AM), is a manufacturing process that builds three-dimensional objects layer by layer from a digital model. This technology allows the creation of...

The natural log of the ratio of absorbed intensity over the total intensity which gives a constant value assuming a stable volume as well as energy. In optical physics the absorbance may be defined...

An accelerometer is a sensor or transducer that measures the rate of change of velocity of an object, or in simpler terms, it measures acceleration. Accelerometers are widely used in various...

An alexandrite laser is a solid-state laser that utilizes a synthetic crystal made from the rare earth element alexandrite (BeAl2O4:Cr3+). This crystal is capable of emitting laser light in the...

An old name for the rotating arm moving about an axis of rotation over a divided circle used to measure angles. Now the term refers to a small stadia telescope mounted over a ruler for use in...

A positively charged particle emitted from the nucleus of an unstable isotope, characterized by two protons and two neutrons. Quantitatively, the equivalent of a helium atom's nucleus.

The use of photographs -- motion picture or still -- to establish if a particular event exists.

The angle formed between a ray of light striking a surface and the normal to that surface at the point of incidence.

The second adjustable iris diaphragm in an optical system. In the common microscope condenser system, it usually is located beneath the substage condenser on a transmitted light microscope. When the...

A physical constraint, often a lens retainer, that limits the diameter of the axial light bundle allowed to pass through a lens.

An apochromat, often referred to as an apochromatic lens or apochromatic objective, is a type of optical system designed to minimize chromatic aberration. Chromatic aberration occurs when different...

An aptamer is a short, single-stranded DNA or RNA molecule that can bind to a specific target molecule with high affinity and specificity. Aptamers are often referred to as chemical antibodies due to...

Area scan, in the context of imaging and cameras, refers to a method of capturing an entire two-dimensional image in a single snapshot or exposure. Unlike line scan, which captures images one line at...

iris or adjustable radially symmetric opening used for allowing the passage of useful light

Radioactivity formed by the bombardment of stable elements by either neutrons or high-energy, charged particles under regulated conditions.

An aspheric lens is a type of lens whose surface profiles deviate from the traditional spherical shape. Unlike spherical lenses, which have a constant curvature across their surfaces, aspheric lenses...

A lens aberration that results in the tangential and sagittal image planes being separated axially.

An astronomical telescope is a type of optical instrument designed to gather and magnify light from distant celestial objects for observation and analysis. It typically consists of two main optical...

An atomic absorption spectrometer (AAS) is an analytical instrument used to determine the concentration of specific chemical elements in a sample by measuring the absorption of light at...

An atomic clock is a highly precise timekeeping device that uses the vibrations or oscillations of atoms as a reference for measuring time. The most common type of atomic clock uses the vibrations of...

Attenuated total reflectance (ATR) spectroscopy is a technique used in analytical chemistry to obtain IR spectra of samples. It is particularly useful for analyzing solid and liquid samples without...

An electronic transducer, either fixed or adjustable, that reduces the amplitude of a wave without causing significant distortion. See also beam attenuator.

Augmented reality (AR) is a technology that integrates digital information, typically in the form of computer-generated graphics, images, or data, with the real-world environment in real-time. AR...

An autocollimator is an optical instrument used for measuring small angular deviations with high precision. It operates on the principle of autocollimation, where a light source is directed onto a...

Automated optical inspection (AOI) is a technology used in manufacturing processes, particularly in electronics, to automatically inspect and detect defects or anomalies in products. AOI systems use...

A system for automatic industrial process control or measurement, consisting of an optical module for image acquisition, a segmentation processor to isolate the image from its background, and an...

In fiber optics, the use of a detector to study the range of refractive indices achieved at various wavelengths. This information is calculated electronically to establish the divergence between...

Calculates the exponential growth of the least stable spatial frequency in a laser beam, and is the numerical equivalent of the nonlinear phase shift along the laser system's optical axis.

In a laser, the series resistance necessary for a stable electrical discharge.

A negative lens used to increase the effective focal length of a telescope objective.

The negative distortion that causes a square grid pattern to be imaged as barrel-shaped.

Laser light show effects equipment including optics and mechanical devices that reflect, position or distort the laser beam, but not including the laser itself.

A beamsplitter is an optical device for dividing a beam into two or more separate beams. A simple beamsplitter may be a very thin sheet of glass inserted in the beam at an angle to divert a portion...

Transmittance of a stable solution is an exponential function of the concentration of the absorbing solute.

An experimental lens used to produce interference fringes. A positive lens is cut into halves along its center, and the halves are separated. This produces a double image of a slit source set...

A type of piezoelectric translator that uses two thin strips of piezoelectric material, one expanding while the other contracts, to produce movement.

A microscope designed with two eyepieces (oculars), permitting the use of both eyes when viewing through the instrument.

A term pertaining to devices (generally optical) designed for use with both eyes viewing through a single exit pupil. The term may be distinguished from binocular in that biocular instruments contain...

Biometrics refers to the automated recognition of individuals based on their physiological or behavioral characteristics. These unique attributes are used to verify or identify individuals, often in...

Also called proximity focus image intensifier. A compact image intensifier that utilizes a microchannel plate intensification stage. This is an in-line device that does not invert the image.

Birefringence is an optical property of certain materials that causes them to exhibit different refractive indices for light of different polarizations. In other words, when light passes through a...

A matrix-controlled display that has information storage at the display surface, and requires that an element be addressed only once to assure that it is on or off.

A source that attempts to create the characteristics of an ideal blackbody. It consists of a cavity, generally spherical, made of an opaque material and insulated from thermal effects, with a small...

Pitch, wax, resin or other cement suitable for holding optical parts to a spindle during grinding and polishing processes.