Photonics Dictionary

A photon-counting instrument for use in both space-borne and ground-based photometric and spectroscopic instrumentation. This style of detector is composed of opaque photocathodes for photon to...

An instrument that contains a spectrograph with a grating in which an array of slits, in place of a photographic plate, is arranged according to the lines of the sample to create an illustration of...

A multiline laser system refers to a type of laser that is capable of emitting multiple discrete wavelengths or spectral lines simultaneously. Unlike single-line lasers, which produce radiation at a...

A specific form of phase shifting interferometry - commonly referred to as multiple wavelength phase shifting interferometry - this form of interferometry utilizes two short wavelengths to synthesize...

Founded by professor Albert Munsell. In the field of colorimetry, the Munsell color system is a color space that identifies a given color based on three different color measurements. These...

A form of shearing interferometer that contains a simple wedged (plane-parallel) glass plate with a nonzero optical path difference to create interference between split optical wavefronts. The...

A quadrivalent semiconductor material, with electrons as the majority charge carriers, that is formed by doping with donor atoms.

A unit of length in the metric system equal to 10-9 meters. It formerly was called a millimicron.

The use of atoms, molecules and molecular-scale structures to enhance existing technology and develop new materials and devices. The goal of this technology is to manipulate atomic and molecular...

An optical pyrometer that is equipped with a narrow bandpass filter to transmit a limited number of wavelengths to the sensing device.

The code used to describe the United States system of color telecasting.

A near-infrared (NIR) spectrometer is an analytical instrument used to measure the absorption, transmission, or reflection of light in the near-infrared region of the electromagnetic spectrum....

When a stereo pair of images is switched so that the right eye sees the left image and the left eye the right, the stereo image perceived will be reversed in terms of relative object depth.

An artificial material, engineered to have a negative refractive index value, such that light or any other form of electromagnetic radiation bends in the opposite direction than it would in ordinary...

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...

A light filter that equally decreases the intensity of all wavelengths of light without altering the relative spectral distribution of the energy.

A telescope with a concave paraboloidal objective mirror and a small plane (diagonal) mirror that reflects rays from the primary mirror laterally outside the tube where the image is viewed with an...

An instrument devised by Nichols and Hull for use in the measurement of radiation pressure. The device has two small silvered, glass mirrors that are suspended, in the way of a torsion balance, by a...

A pollution-measuring device used to detect the presence of nitric oxide regardless of other gases present. It utilizes the principle of laser magnetic resonance (LMR).

The measurement of first- and higher order properties of a lens and its formed image, including effective focal length, back focal length, f number, aberrations, blur patterns, magnification and...

In a thermal imaging system, the change in temperature that yields a signal-to-noise ratio of unity.

Any testing method for materials and components that does not damage or destroy the test sample. Some of the methods used are x-ray, ultrasonic, electro-optic and magnetic testing.

A type of radiation detector designed to recognize nonlinear optical effects, such as the Raman effect, by means of a directional, nearly monochromatic light beam; e.g., a laser beam.

Nonlinear optical materials are substances that exhibit optical properties that are not linearly proportional to the intensity of incident light. In other words, these materials produce optical...

Direct conversion of a photon from one wavelength to a lower energy photon of another wavelength(s) due to inelastic scattering. In an optical waveguide, nonlinear scattering is usually not important...

Also referred to as a band-stop or band rejection filter; a notch filter is a filter that is designed to screen out a very narrow band of radiation by transmitting most wavelengths with little...

A filtering device that detects what is new in a scene of interest. Often compared to that of a temporal high pass filter, these filters will remove elements that appear repeatedly throughout an...

In image acquisition (and sampling theory), the postulate that the pickup sampling frequency must be a minimum of twice as high as the Nyquist rate of brightness change of any detail to be resolved....

An electro-optical infrared tracker consisting of a beamsplitter, an illuminating source, an image dissector tube and an electronics unit, that automatically acquires and tracks particular eye...

A polished plano-parallel plate that is contacted to an unpolished glass surface to permit see-through analysis of the material. The plate eliminates effects because of the surface quality of the...

An instrument for measuring opacity.

An interface in an optical network that permits an optical signal to pass without changing the optical signal to an electrical signal and therefore does not limit the signal to a specific protocol.

See eye test apparatus; ophthalmic instruments.

Directing an optical beam in varying directions by varying reflection, refraction, focusing and diffraction methods.

The point on the optical axis of a lens that is the image of the nodal points. For any bundle of rays passing through the optical center of a lens, the incident and emergent rays through this point...

A photosensitive device used to optically scan and read character data (numbers, letters etc.) and input this data into a storage device. Optical character readers are based off the process of...

Optical character recognition (OCR) is a technology that is used to convert printed or handwritten text into machine-readable text. OCR software and systems are designed to recognize and extract...

Optical coherence tomography (OCT) is an imaging technique used in medical diagnostics and biomedical research to obtain high-resolution, cross-sectional images of biological tissues. An OCT imaging...

An instrument used to measure backscatter as well as optical return loss and reflectance within an optical fiber system by measuring the reflected light when a continuous wave is transmitted through...

A small low-power microscope or magnifier with a scale that is used to measure the exit pupil diameter and eye relief on visual instruments. Optical dynameters are often used to measure the...

Mathematically defined as the product of etendue (or throughput) and the square of the refractive index, the optical extent is the quantitative value that describes the geometrical limit to how much...

An optical filter is a device that selectively transmits or blocks specific wavelengths, or colors, of light. Optical filters are used to control the spectral content of light in various...

An optical gate typically refers to a device or system that controls the transmission of light, allowing it to pass through or be blocked in a manner analogous to an electronic gate controlling the...

The use of photonic devices rather than electronic devices to make connections within and between integrated circuits.