Photonics Dictionary

Usually a dielectric coating on glass or plastic optics; a coating that is comparable in hardness to glass itself.

Text or images printed on paper or another tangible medium, as opposed to those viewed electronically on a cathode-ray-tube screen.

High-modulus elastic fibers that exhibit the following differences from conventional elastic fibers: Increasing temperature decreases recovery force (the fibers are enthalpic vs. conventionally...

The process of sealing laser components by means of frit seals, welding or bonding rather than using epoxy.

A type of x-ray that is capable of deep penetration; its wavelength is about 10-8 cm.

A type of optical fiber in which a silica core is surrounded by a hard polymer or similar material much stronger than the customary cladding material.

In the most general sense, the resistance of a solid surface to damage.

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...

Glass that has been treated by the case-hardening process.

Observed phenomenon of a small developed image with higher density than a larger image because of variation in photographic plate densities with variations in size of opening.

A measurement of the hardness of a material as determined by the penetration depth of a diamond stylus under a specified amount of pressure.

Material hardness scale that is used to characterize the scratch resistance of various materials. This surface hardness evaluation is determined by scratching the surface to be tested with 10...

Rockwell hardness (Rc) refers to a method for measuring the hardness of a material, primarily metals, using an indentation test. It is named after the Rockwell scale, which was developed by Stanley...

A test similar to the Knoop hardness test, but used for fractured material. The indenter is a square-based pyramid-shaped diamond.

The penetrating capacity of x-rays that is an inverse function of the wavelength.

An electron tube whose electrical characteristics will not be affected by gaseous ionization because of its high degree of evacuation. Also known as a hard tube.

A thermoplastic or optically transmitting hard plastic produced by applying polymerization initiator and heat to a monomer.

A relatively hard crystal, highly resistant to excessive energy radiation, that is frequently used for optical windows, prisms and lenses transmitting from the vacuum UV into the IR.

An instrument designed to produce very hard x-rays by the acceleration of electrons in a varying magnetic field.

A device for the internal inspection of hard-to-get-at mechanical parts, such as rifle barrels, sewer pipes, oil wells, or gas mains. The long narrow tube used contains a telescope system with as...

A doubly refracting mineral used to produce polarizing prisms. It is uniaxial negative and in the trigonal division of the hexagonal system of crystals. Its indices are e = 1.486, w = 1.658; its...

An instrument consisting of a high-voltage vacuum tube used to form hard x-rays or high-speed ion beams. By partitioning the tube into separate sections, the total voltage is divided.

Computer hardware or firmware that accesses character patterns stored in read-only memory and displays them at specific coordinates on a screen.

CoaXPress (CoaXPress or CXP) is a standardized digital interface and communication protocol used primarily in machine vision and industrial imaging applications. It enables high-speed data...

Hardware installed on fiber cable ends to provide cable attachment to a transmitter, receiver or other cable. Usually a device that can be connected and disconnected repeatedly.

One of the two principal types of optical glass, the other being flint glass. Crown glass is harder than flint glass, and has a lower index of refraction and lower dispersion. Both types are used in...

A solid with a structure that exhibits a basically symmetrical and geometrical arrangement. A crystal may already possess this structure, or it may acquire it through mechanical means. More than 50...

The naturally occurring crystalline form of silicon dioxide. It is slightly birefringent and exhibits rotary dispersion of light rays transmitted along the crystal axis, both right-hand and left-hand...

Deep learning is a subset of machine learning that involves the use of artificial neural networks to model and solve complex problems. The term "deep" in deep learning refers to the use of deep...

Diamond turning, also known as diamond machining or diamond cutting, is a precision machining process used to produce high-quality optical surfaces and components with extremely tight tolerances. It...

A very hard, highly transparent coating based on forms of carbon, used to protect optical components from abrasion and chemical damage.

The technique by which an analog image is converted by any of several means into a finite array of points, each represented by some numerical value. Once created, this array can be the basis of a...

Medical diagnostic (x-ray) imaging using laser printers to produce high-resolution digital hard copy instead of film exposed by phosphor-intensifying screens, thus providing radiologists with greater...

The hardware for reading (and writing in devices so equipped) an optical mass data storage disk.

An Er:YAG laser is a type of solid-state laser that uses a crystal made of erbium-doped yttrium aluminum garnet (Er:Y3Al5O12) as the gain medium. The erbium (Er) ions are introduced into the crystal...

The process whereby a rotating wheel carries grains of an abrasive, suspended in a vehicle, across the surface of the optical glass to be ground. The workpieces are forced downward by pneumatic...

A computer hardware unit that generates required functional information on the screen by controlling CRT beam movements or intensity.

A method of determining the abrasion resistance of very hard materials by passing a weighted wiper blade across them in a sand-water slurry for a specified number of times.

The process of subjecting glass to temperature cycling to produce physico-chemical reactions that alter its properties. Similar processes can be accomplished with a laser -- most commonly a CO2,...

1. The process of wearing down the surface of a softer material by rubbing it under pressure against the surface of a harder material that has been formed in the shape opposite to that desired on the...

A process of forming ions within a given molecular species by incident laser light. The molecular species may remain intact, without fragmentation, during soft desorption whereas molecular samples...

A machine vision system is an integrated combination of hardware and software components designed to capture, process, and analyze images to perform automated inspection, measurement, and quality...

An adhesive used to hold optical components in their mounts. It may be a thermoplastic or chemical-hardening substance.

A network interface card (NIC), also known as a network adapter or LAN adapter, is a hardware component that allows computers to connect to a local area network (LAN) and communicate with other...

An optical assembly refers to a collection of optical components that are carefully arranged and aligned to perform a specific function within an optical system. These components may include lenses,...

Optical materials refer to substances or compounds specifically chosen for their optical properties and used in the fabrication of optical components and systems. These materials are characterized by...