Photonics Dictionary

Spin coating is a widely used technique in the fabrication of thin films and coatings, particularly in microelectronics, optoelectronics, and nanotechnology. It involves depositing a liquid precursor...

A defect in the cleaved end face of an optical fiber in which the surface changes abruptly.

A vacuum deposition method in which the coating material (target) is removed from the surface of the coating source (cathode) by ion bombardment and deposited upon the substrates.

Sputtering equipment is machinery used in the process of physical vapor deposition (PVD), specifically sputtering. Sputtering is a method of depositing thin films of material onto a substrate surface...

A sputtering target is a solid material used in the process of physical vapor deposition (PVD), specifically sputtering. Sputtering targets are typically made of metals, metal alloys, or compounds...

A profile of an optical component, usually a fiber, in which the core is of uniform refractive index and the cladding or surrounding optical surface of a different, usually lower, index.

The unit solid angle subtended at the center of a sphere by an area on its surface equivalent to the square of the radius; the unit of solid angular measurement, often used in problems of...

A polishing machine with a lens mounted on a wooden stick, allowing a very wide sweep. It is used to polish hemispherical or hyper-hemispherical surfaces.

The fine scratches formed when, in hand centering, the forked stick used to move the lens on the chuck marks the rotating lens surface.

In positioning, the friction that prevents immediate motion when force is first applied to a body or surface at rest.

A method of polishing an aspheric surface by mechanically distorting the optic while polishing the surface to a perfect sphere. When the stress is released, the substrate assumes the desired aspheric...

A pulsed interferometer that permits the continuous quantitative mapping of the surface deformation of an adaptive optical element (e.g., a deformable mirror) and provides the capability for...

A method used in surface quality testing for accurate positioning and rotation of metal spheres about an axis or fixed point in space that involves a sliding contact between the indicator and tip and...

A measuring instrument used for surface profiling and quantifying the roughness of a material. The stylus is placed on the surface of the material at a given contact force, then is moved laterally...

A substrate refers to a material or surface upon which another material or process is applied or deposited. In various fields, such as electronics, biology, chemistry, and manufacturing, the term...

A reflector having a surface that has been superpolished to reduce residual sleeks and scratches and microroughness so that its scatter coefficient is low. Its surface is said to have a low-scatter...

1. In optics, one of the exterior faces of an optical element. 2. The process of grinding or generating the face of an optical element.

(SALI) A type of spectroscopy in which neutral atoms or molecules are ionized by an excimer laser beam and then measured by a time-of-flight mass spectrometer.

Waves that propagate along the interface between two different media without radiation with exponentially decaying evanescent fields on both sides.

The departure of an optical surface from its required tolerance or figure.

A large table with an accurately designed plane surface used to test other surfaces, or to provide a true surface for accurately locating a testing fixture. Most commonly made of granite.

A representation of the shape of a surface, including any roughness or other irregularities. The profile can be generated by direct measurements, as by a stylus, or by remote measurement, as by an...

The specification of allowable flaws in a surface by comparison to reference standards of quality. Two graded sets of surface quality standards are employed. The first denotes defects of a long...

The standards of MIL-O-13830 set by the US government relative to tolerable surface scratches and other such defects in an optical system. A series of standard glass plates that have been...

Also known as Fresnel reflection. That portion of the incident radiation that is reflected from the surface of a refractive material. It is a function of the refractive index of the material. At...

A wave that is guided by the interface between two different media or by a refractive index gradient in the medium. The field components of the wave may exist (in principle) throughout space, even to...

A semiconductor laser diode that emits light perpendicular to the active region. The output radiation is taken through the surface as opposed to through a cleaved mirror.

A technique of optical storage whereby information is encoded by molecular alterations in the interaction between the optical layer and the substrate.

Surface-enhanced Raman scattering (SERS) is a powerful analytical technique that enhances the Raman scattering signal of molecules adsorbed on or near certain nanostructured surfaces. Raman...

Surface-enhanced Raman spectroscopy (SERS) is an analytical technique that combines the principles of Raman spectroscopy with the enhancement provided by nanostructured metallic surfaces. Raman...

A surface-mount device (SMD) is an electronic component that is mounted directly onto the surface of a printed circuit board (PCB) rather than being inserted into holes drilled in the board (as with...

Surface-mount LEDs (SMD LEDs) are light-emitting diodes designed for mounting directly onto the surface of printed circuit boards (PCBs) without the need for leads or wires. Unlike traditional...

An instrument used to measure the luminance (brightness) of a distant object. The object is viewed through a small telescope, and a mirror in the focal plane reflects an internal illuminated surface...

A glass that is heated, then chilled (usually by an air blast) to set up internal stresses so that the surfaces are under compression. This strengthens the glass, since glass breaks only in tension,...

A device used to detect elevation, pyramid and resolution errors in prisms and other components by bringing them into contact with the three highly polished, flat, perpendicular surfaces that form...

A transparent block shaped accurately to reverse curvatures of the components it is used to test. By contacting an accurately finished negative lens shape with a newly made positive, the conformity...

A contraction for "texture element." A base unit used in computer graphics that defines the surface of three-dimensional objects. Texels are obtained from texture memory and represent color to be...

Thermal interface materials (TIMs) are substances or compounds used to enhance the thermal conductivity between two surfaces in contact. These materials are primarily employed in electronic devices,...

Thermography is a technique that involves the use of an infrared imaging device, called a thermal camera or infrared camera, to detect and visualize the infrared radiation emitted by objects. This...

Thermophotovoltaic (TPV) refers to a technology that converts heat energy into electricity using the principles of thermophotovoltaics. In a thermophotovoltaic system, thermal radiation from a heat...

A display device having a thermoplastic film as the control layer medium. The film, moving from a playoff reel, is scanned by an electron gun and melted by an RF heating unit. Deformation of the film...

Thin-film coatings are layers of material applied to the surface of an object or substrate, typically to modify its optical, electrical, or mechanical properties. These coatings are composed of thin...

Thin-film deposition equipment refers to machinery and tools used in the process of depositing thin layers of material onto a substrate surface. This technique is commonly employed in various...

Thin-film deposition is a process used to deposit a thin layer of material onto a substrate surface, typically ranging from nanometers to micrometers in thickness. These thin films are utilized in...