Photonics Dictionary

An absorption lens is a type of optical lens that not only focuses or diverges light but also significantly absorbs certain wavelengths of the incident light. This dual function makes it different...

AC thin film electroluminescent (ACTFEL) display devices are a type of flat-panel display technology that uses electroluminescence to produce visible light. Structure: They consist of a thin...

Optic surface cleaning liquid that may be applied to glass, crystal, dielectric and metal surfaces; however, may not be applied to plastic and polymer materials.

An achromat, in the context of optics, refers to a type of lens or lens system designed to reduce chromatic aberration. Chromatic aberration is an optical phenomenon where different colors of light...

An achromatic lens is a type of optical lens designed to minimize chromatic aberration, which is the inability of a lens to focus all colors of light to the same convergence point. Chromatic...

An acousto-optic deflector (AOD) is a type of device that utilizes the acousto-optic effect to control the direction of light beams. It operates by modulating the refractive index of an optically...

An acousto-optic modulator (AOM) is a device that utilizes the acousto-optic effect to modulate the amplitude, phase, frequency, or polarization of a laser beam or other coherent light source. It...

An acousto-optic tunable filter (AOTF) is a device that utilizes the acousto-optic effect to selectively filter and transmit light based on its wavelength or frequency. It operates by applying an...

Acrylic refers to a type of synthetic polymer material known for its versatility, clarity, and durability. It is commonly used in a wide range of applications due to its beneficial properties. Here...

An active-matrix display is a type of flat-panel display technology where each pixel is actively controlled by one or more thin-film transistors (TFTs). This technology is commonly used in liquid...

Visual acuity specifically refers to the clarity or sharpness of vision, typically measured by the ability to discern the details of objects at a specific distance. It is a fundamental measure of the...

An intermolecular substance that serves to hold materials together. Two types are used in the optical industry: one, which must be transparent and colorless, to cement lenses together; and a...

Commonly known as CR39, this thermosetting plastic is used in the casting of eyeglass lenses because of its toughness and clarity.

The underexposed collodion that is present on a glass negative as a positive when backed with material.

The disordered, glassy solid state of a substance, as distinguished from the highly ordered crystalline solid state. Amorphous and crystalline phases of the same substance differ widely in optical...

A glass or metal measurement tool having a precisely calibrated angle between two of its faces.

The process of heating and slowly cooling a solid material, like glass or metal, to stabilize its thermal, electrical or optical properties or, as in semiconductor materials, to reverse lattice...

An oven or furnace that possesses the design requirements and heat control necessary to anneal glass for the optical industry.

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 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...

An astronomical mirror, also known as a telescope mirror or primary mirror, is a key component of a reflecting telescope. It serves as the primary optical element responsible for gathering and...

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 axicon is a type of optical component characterized by its conical shape and its ability to transform a collimated Gaussian beam of light into a ring-shaped beam with a gradually increasing...

A device containing two opposed quartz wedges of equal angle, one wedge being movable along its length by a micrometer screw. The wedges are cut so that their fast directions are along, and...

A glass substrate that has its rear surface coated with a reflective coating. Also known as a back-surface mirror.

A ball lens is a small, spherical optical component typically made of glass or other transparent materials. It is characterized by its spherical shape, with both its front and back surfaces forming...

The application of reversible writing with a laser beam on particular storage materials. In one method, an amorphous film is heated and then crystallized for writing. Bubble writing involves the...

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

Device used to measure the numerical aperture of a microscope, composed of a 14-mm-thick glass block with numerical aperture gradations carved onto its lower surface.

A two-part lens that has a different focal length for each part. Generally, it is used in eyeglasses to correct for both near and far vision.

A piece of glass polished flat on one side, with a pair of polished faces that form an angle close to 180° on the other side, the dividing edge running down the middle of the plate. It is used...

A piece of glass, quartz or other transparent material formed roughly by molding or cutting into the approximate shape and size of the finished part.

An extended bubble or seed on glass, elliptically shaped and more than one-quarter inch (6.3 mm) in length.

In the optical field, a piece of glass to which a lens or prism is cemented. The unit is ground and polished as a whole to obtain a sharp edge on the finished piece.

A parallel plate of glass in such a position that the refracted and reflected rays of incident parallel light are mutually perpendicular. In this situation the reflected light is plane polarized, and...

A piece of glass with a high refractive index that is fused to the major blank.

An optical material used in place of crown glass to produce lenses with extraordinary correction of chromatic aberrations. Its high coefficient of thermal expansion and its tendency to absorb...

A surface heat-treating process that produces a highly stressed surface. In case-hardening of glass, a plate of glass is heated almost to the softening point and then cooled quickly in a blast of...

Envelopes for cathode-ray tubes are made by blowing glass in the same manner as light bulbs. They have a fairly flat end face to carry the phosphor material applied internally.

A fiber optic end plate constructed by drawing a bundle of parallel fibers embedded in glass and cutting it into thin slices. These slices are assembled in a plane and heated to produce a...

Chalcogenide refers to a class of compounds containing elements from group 16 of the periodic table, which includes sulfur (S), selenium (Se), and tellurium (Te). These elements are known as...

A photoelectric detector consisting of a glass tube internally coated with a low conductance material. Voltage applied along the tube causes photoemission from the photocathode at the end of the tube...

Chemical vapor deposition (CVD) equipment refers to a class of specialized apparatus used in the process of chemical vapor deposition, a technique for depositing thin films of various materials onto...