Photonics Dictionary

In infrared imaging systems used for mass screening of printed circuit boards or other quality control applications, an image of an ideal component that is stored in the system's memory and then...

A projection printer that is capable of reproducing a multiplicity of images from a master transparency on a single support coated with a photosensitive layer by indexing the receiving material from...

An approach to character recognition based on the structure of the character to be identified (number of straight lines, bays, holes, etc.); used where simple matching is not viable, as in...

Structural color refers to coloration in materials that is not caused by pigments or dyes but is instead a result of the physical structure of the material. In structural color, the interaction of...

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...

Supercontinuum refers to a broad spectrum of light that spans a wide range of wavelengths, typically from the visible to the near-infrared or even mid-infrared regions of the electromagnetic...

Superluminal transmission refers to the hypothetical process of transmitting information faster than the speed of light, which is commonly denoted as superluminal or faster-than-light (FTL)...

Superresolution refers to the enhancement or improvement of the spatial resolution beyond the conventional limits imposed by the diffraction of light. In the context of imaging, it is a set of...

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...

A swept-source laser, also known as a wavelength-swept laser, is a type of laser that rapidly and continuously changes its emission wavelength over time. This continuous wavelength tuning is achieved...

A synchrotron is a type of particle accelerator that uses magnetic fields to steer charged particles, typically electrons or positrons, in a closed, circular or elliptical path. The name synchrotron...

A telescope lens is a primary optical component of a telescope system that gathers and focuses light to form an image. It is typically a curved, transparent piece of glass or other optical material...

The span of frequencies within which a single channel of broadcast television must fall; in the US, it is 6 MHz.

An electronic device used to encode video and audio signals of a television camera into radio waves that are broadcast to remote receivers. The video and audio components are transmitted...

Operation in which the minimum detectable signal has its limits set by the thermal noise of the detector, the load resistance and the amplifier noise.

A laser having a material, such as ruby, that has an energy state structure of three levels: the ground state (1) wherein excitation applied to the material raises ions in the material into the...

Three-photon microscopy is an advanced imaging technique that belongs to the family of multi-photon microscopy methods. It is used in biological and medical research to capture high-resolution images...

Time-lapse optical coherence tomography (OCT) refers to a medical imaging technique that captures a series of sequential OCT scans over time, allowing for the dynamic observation and monitoring of...

A Ti:sapphire laser is a type of solid-state laser that utilizes a titanium-doped sapphire crystal as the gain medium. The name Ti:sapphire comes from the combination of titanium (Ti) as the dopant...

Imaging materials that generally consist of a polyester base, a transparent electrically conductive layer and an organic photoconductive top coating. When charged and exposed to light, an...

Oscillator device composed of a semiconducting diode in a coaxial resonating cavity. When the biasing current is applied to the diode, high-frequency waves are emitted into the cavity where they are...

A semiconductor device that functions as an electrically controlled switch for AC loads.

A form of liquid crystal widely used in displays, achieved by sandwiching a liquid crystal material between two substrates whose inside surfaces have been prepared with a special coating that aligns...

An ultrafast pulsed laser is a type of laser that emits extremely short pulses of light with durations typically on the order of femtoseconds (10-15 seconds) or picoseconds (10-12 seconds). These...

Ultraviolet (UV) fiber optics refers to optical fibers that are designed and optimized for the transmission of ultraviolet light, which is electromagnetic radiation with wavelengths shorter than...

Ultraviolet reflectance refers to the ability of a material or surface to reflect UV light. Ultraviolet light is electromagnetic radiation with wavelengths shorter than those of visible light,...

An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without a human pilot onboard. UAVs are remotely controlled or autonomously operated, and they can be used for various...

Equipment dependent on the effects of a vacuum. The principal applications in optics are in the coating of lenses and substrates and the fabrication of multilayer interference filters.

A method of cleaning and drying coated optical components. The cooled parts are placed in a container above a boiling solvent, whose vapors condense on the parts. When the parts reach the temperature...

A small television tube originally developed for closed-circuit television. It is about 1 inch in diameter and 5 inches long. Its controls are relatively simple and can be operated by unskilled...

Virtual reality (VR) is a computer-generated simulation of a three-dimensional environment or experience that can be interacted with and explored by an individual using electronic devices, such as a...

Volume Bragg gratings (VBGs) are specialized optical elements that consist of periodic variations in refractive index throughout the volume of a transparent material, typically a photosensitive glass...

A vortex phase plate is an optical device designed to impart a phase singularity, commonly referred to as a vortex or phase vortex, onto a light beam. This singularity results in a phase profile...

A wide-angle lens is a type of camera lens that has a shorter focal length than a standard or normal lens, allowing it to capture a broader field of view. Wide-angle lenses are characterized by their...

A method that embraces the classical approach to image restoration and attempts to minimize the mean square difference between the original ungraded signal and the restoration.

A film or plate that is usually coated on both sides with a very fast emulsion that is sensitive to x-rays, and used to record x-ray diffraction patterns photographically.

A diagnostic instrument that uses a photocathode design to see a broad range of x-ray radiation by streaking the photographic image continuously in time. It produces time- and space-resolved...

A highly flame-retardant material used to jacket fiber optic cables, especially on shipboard applications.

A quarter- or half-wave retarder made from two plates of quartz, mica or polymer with their fast axes crossed; the difference in thickness between the two plates determines the retardance. Zero-order...