Photonics Dictionary

The visual phenomenon of the apparent difference in the rate of motion of two objects that are actually moving at the same velocity but that lie at different distances from the observer.

The unequal angular velocities of two objects moving at equal speeds but at different distances from the observer, which are just noticeable.

The visual perception of motion when fixed stimuli are exposed in rapid temporal and spatial succession.

The adjustment of the eyepiece of an instrument to provide accommodation for the eyesight differences of individual observers. The axial distance through which the eyepiece must be moved, to provide...

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...

An active infrared (IR) system is a type of technology that uses infrared radiation actively emitted and detected by sensors for various purposes. Here are the key features and applications of active...

In the context of semiconductors and electronics, the active layer is the part of a semiconductor device where the essential electronic activities take place. This includes the movement and...

An actuator is a mechanical or electromechanical device that is responsible for moving or controlling a mechanism or system. It converts various forms of energy (such as electrical, hydraulic,...

Eye blink or head movement in response to bright light. Aversion responses such as blinking are sufficient protection from less hazardous lasers, including Class 2 lasers. An eye blink can occur, at...

A type of piezoelectric translator that uses two thin strips of piezoelectric material, one expanding while the other contracts, to produce movement.

Bin picking, also known as bin picking automation or bin picking robotics, refers to the automated process of selecting and retrieving individual objects or components from a bin, container, or bulk...

Bioelectricity refers to the electrical potentials and currents generated by biological processes within living organisms. These electrical phenomena arise from the movement of ions across cell...

Carrier injection refers to the process of introducing charge carriers (either electrons or holes) into a semiconductor material. Semiconductors are materials with electrical conductivity between...

Cell migration refers to the process by which cells move from one location to another within tissues or across biological barriers. This fundamental biological process is essential during various...

The mark formed when the movement of the lens over the face of the centering chuck abrades the surface.

Circular-ranging optical coherence tomography (CR-OCT) is a specialized imaging technique used in medical diagnostics and research to obtain high-resolution cross-sectional images of biological...

A colloid is a mixture in which one substance of microscopically dispersed insoluble particles is suspended throughout another substance. The particles in a colloid are larger than those in a...

The attribute of visual experience that can be described as having quantitatively specifiable dimensions of hue, saturation, and brightness or lightness. The visual experience, not including aspects...

The use of a computer to generate a series of interrelated images so that the images give the illusion of movement in space and time.

Computer numerically controlled (CNC) grinding is a manufacturing process that utilizes computerized controls and precision machining tools to remove material from a workpiece. In CNC grinding, a...

The selective absorption of electromagnetic waves by a liquid made up of molecules with permanent dipole movement.

Dual-axis laser is a laser device or system capable of emitting laser beams along two orthogonal axes (typically X and Y axes) concurrently. This allows for precise control and manipulation of the...

The control of free electron movement through the use of electrical or magnetic fields, and use of this electron movement in research investigation of electronic diffraction phenomena, directly...

An electron-beam lithography (EBL) system is a sophisticated nanofabrication tool used in the semiconductor industry and research laboratories to pattern extremely fine features with sub-micrometer...

The movement of particles or ions in a solution toward the electrode having the opposite sign because of the application of an electrical field.

An electrophoretic display, often referred to as an electronic paper display or e-paper display, is a type of electronic visual display technology used in electronic devices for the purpose of...

An emission spectrum is a graphical representation or a characteristic pattern of the wavelengths or frequencies of light emitted by a source, such as an atom, molecule, or celestial object. It shows...

The movement of particulate material by flowing gas or liquid.

An exciton is a quasiparticle that represents the bound state of an electron and a hole in a solid-state material, typically a semiconductor or an insulator. In simpler terms, an exciton is a paired...

An optical device used to monitor movement of the human eye.

A secondary halo whose movement counterpoints the behavior of the Becke line.

In various fields such as fluid dynamics, microfluidics, and biotechnology, a flow channel refers to a defined pathway through which a fluid (liquid or gas) flows. The channel can be of various...

Fluorescent proteins are proteins that exhibit the property of fluorescence, which is the ability to absorb light at a specific wavelength and emit light at a longer wavelength. These proteins are...

The length of the small space within which the atmosphere exhibits coherence, particularly in relation to an observer on Earth viewing celestial objects. The turbulence of the Earth's atmosphere...

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

Machinery used to grind and finish a component, such as a lens or prism, to a desired precision. Usually such machines carry a cup-shaped or flat tool (lap) into close contact with the part. An...

A gyroscope is a mechanical device consisting of a spinning disk or wheel mounted on a spinning axis in such a way that its orientation remains fixed regardless of any movement of its mounting...

Gyroscopy refers to the principles and applications of gyroscopes, devices that measure or maintain orientation based on the principles of angular momentum. Gyroscopes are essential in various...

A method used in facsimile scanning that sweeps the elemental area across the copy in a spiral motion as the result of the movement of a single turn helix against a stationary bar.

A heterojunction is a junction formed between two different semiconductor materials with differing band gaps. These materials can be of the same or different types (e.g., both n-type, both p-type, or...

The active control of various aspects (optical element position, airspace thickness, etc.) of an optical system that compensates for unwanted movement of the image that is caused by mechanical and...

Photogrammetric compensation for incidental camera movement (which prevents attainment of true vertical photographs) whereby the imagery is copied in an oblique plane camera system.

Generally, a rotatable table with scales marked in degrees. The fiducial marking also may be a vernier scale. The same scheme is applied to linear movement. Such devices are often applied to...

In a camera, the movement of one or more lenses behind the front lens, rather than of the front lens itself, to bring the subject into focus. Because internal focusing does not require the front lens...

An interband cascade laser (ICL) is a type of semiconductor laser that operates based on interband transitions between energy bands in a semiconductor material. Unlike traditional semiconductor...

A mount for an optic element or optics assembly, designed so that all six degrees of freedom are singly constrained. This assures that movement will be prevented, while stress will not be introduced...