Photonics Dictionary

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...

Actinic refers to the property of radiation, particularly ultraviolet (UV) light, that can cause photochemical reactions. Radiation: Actinic radiation typically involves UV light but can also...

Actinic focus refers to the point or plane within an optical system where ultraviolet (UV) light or other actinic radiation converges to form the sharpest possible image. Here are the key aspects: ...

Actinic glass is a type of glass specifically designed to filter or block ultraviolet (UV) light and other forms of actinic radiation. UV filtering: Actinic glass effectively absorbs or...

Actinic radiation refers to electromagnetic radiation that has enough energy to induce photochemical reactions. This type of radiation is primarily in the ultraviolet (UV) range but can also include...

The actinides are a series of 15 chemical elements in the periodic table, with atomic numbers from 89 to 103. They are named after actinium, the first element in the series. Elements: The...

Actinism refers to the property of radiation, particularly light, that enables it to produce photochemical effects. This term is derived from the Greek word aktinos, meaning ray. Here are the key...

Actinochemistry refers to the branch of chemistry that studies the chemical effects of radiation, particularly light, on substances and chemical reactions. Here are the key aspects of...

An actinometer is a device used to measure the intensity of radiation, particularly solar radiation or light, often with a focus on its ability to cause photochemical reactions. Here are the key...

Actinometry refers to the measurement of the intensity of radiation, particularly light, with a specific focus on its ability to cause photochemical reactions. It involves quantifying the amount of...

Alternating current (AC) is an electrical current in which the direction of flow of electric charge periodically reverses. This reversal occurs at regular intervals, typically in a sinusoidal...

A coating that is capable of stopping the condensation of moisture on an optical surface.

An antireflection coating (AR coating) is a thin film or coating applied to optical surfaces, such as lenses or windows, to minimize unwanted reflections and increase the transmission of light...

An electrically conductive layer for carrying off static charges that might accumulate on a surface.

A spectrograph in which the refracted beam returns almost along the path traveled by the incident beam, and is brought to a focus by the lens that collimates the incident beam.

The forming of a clear silhouette of an object by placing a light source behind it. Used in machine vision when surface features of an object are not important.

A glass block that produces stationary fringes in the region crossed by incident light beams.

In photography, the technique of taking multiple pictures of the same subject at different exposures to compensate for exposure miscalculations. Automatic bracketing is a feature on some cameras.

A filter that separates light into many colors via Bragg's law. Generally refers to a fiber Bragg grating used in optical communications to separate wavelengths.

The surface of an element of a compound lens that will produce the cemented interface. The curves of this interface are called inside curves. To facilitate cementing, the two inside curves should...

Any of several compounds capable of binding heavy-metal ions, thereby preventing interaction between the bound ions and the rest of the medium.

A light-sensitive detector having a chemical compound that reacts when exposed to light. It is used in photochemistry and relies on the chemical reaction to determine the amount of incident radiation.

A method of applying antireflection coatings to optics that avoids the elevated temperatures normally used. A cold coating will not be as durable as a normal coating.

A type of compound microscope that uses three visible wavelengths to translate details produced by invisible radiation.

The heat-treating method in which the index of refraction of glass is fixed near or at its maximum value by holding the glass for different periods at suitable degrees of heat below the range of...

A microscope eyepiece designed for use with apochromatic objectives. Since apochromatic objectives are undercorrected for lateral color, these eyepieces are overcorrected for that aberration.

A filter used in photography to change the spectral composition of light entering a camera, or to adjust color balance during printing.

Also known as clear glass or clear filter. The clear glass plate is used to simulate a filter, in converging or diverging light, to maintain focus.

A reflecting grating ruled on a concave spherical surface that not only disperses the light but focuses the spectrum. The great advantage of this grating lies in the fact that no separate collimating...

The generation of a grating on a concave spherical blank by the holographic process. In this way, ghost images and intense stray light are avoided.

The radiation spectrum of matter found in condensed states, liquid or solid, that is continuous and not a line spectrum. The details of this spectrum are almost independent of the matter emitting the...

A continuous strobe, also known as a continuous light or constant light strobe, is a type of lighting device used in photography, videography, and various other applications where continuous...

Continuous wave (CW) refers to a type of signal or transmission where the signal is constant and does not vary with time. In various contexts, the term is used to describe continuous, uninterrupted...

A laser that emits radiation continuously rather than in short bursts, as in a pulsed laser.

In microscopy, the chamber that is contained on a microscope slide to hold a certain amount of fluid. It is calibrated accurately to determine the number of cells and other elements while the...

A crystal that may serve as a diffraction grating if mounted effectively.

The process of forming a lens to a given pattern, or of cutting a piece of glass along the line of scratch.

The point on a cutting line that will become the geometrical center of the cut lens.

A Dammann grating is a type of diffractive optical element (DOE) used to create an array of equally spaced, uniform-intensity spots or beams. It is named after its inventor, Dr. Herbert Dammann. The...

Design and engineering consulting services refer to professional services provided by specialized firms or individuals to assist clients in various aspects of product development, system design, or...

Dewetting is a phenomenon in materials science and physics where a thin film or coating spontaneously undergoes a process of breaking up and forming isolated droplets on a substrate. This occurs due...

A tool made by imbedding small particles of diamond in the working edge. In the optical field, the most commonly used diamond tools are glass saws, cup-shaped tools for curve generators, and diamond...

A dichroic coating, also known as a dichroic filter or dichroic mirror, is an optical coating designed to selectively transmit or reflect certain wavelengths of light while simultaneously absorbing...

A shallow, fine-pitch diffraction grating having a precise dielectric overcoating that experimentally has absorbed wavelength-specific incident light that is polarized in the P-plane.

A high-reflectance coating consisting of alternating layers of quarter-wave film of a higher refractive index and lower refractive index than the substrate. Such coatings can be made very specific to...