Photonics Dictionary: O

The transmission and reception of information by optical devices and sensors.

One or more optical elements – typically cemented together - in an optical system that are treated as a single group; e.g., a beamsplitter, or a cemented doublet or triplet.

The adhesion of two sufficiently clean and close-fitting surfaces without the use of cement or glue. The optically contacted surface is almost as durable as the body of the glass, and the surfaces...

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...

The procedure by which the similarity of an optical signal or waveform to a reference-stored signal or waveform is determined. Generally the reference is stored as a matched filter.

A device incorporating a spatial light modulator and a reference filter; used for matching an input optical waveform or signal with stored data in a photonic computer. This technique is done using...

A measure of the transmittance through an optical medium. Optical density equals the log to the base 10 of the reciprocal of the transmittance. where τλ is transmittance. In spectroscopy,...

Optical design and engineering services involve the development, customization, and optimization of optical systems and components to meet specific performance requirements and application needs....

Optical design software refers to specialized computer programs used by optical engineers, physicists, and designers to simulate, model, analyze, and optimize the performance of optical systems and...

A rigid medium, generally a polycarbonate substrate coated with a reflective aluminum layer, that stores information (such as audio, video or data) as digital bits in the form of variations in the...

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...

An optical part constructed of a single piece of optical material. It is usually a single lens, prism or mirror.

A device designed to measure linear or rotary motion by detection of the movement of markings on a transparent medium past a fixed point of light. The encoder has a moving code plate, a glass disc...

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...

Optical fiber optic switches are devices used in optical fiber communication systems to selectively route optical signals from one input fiber to one or more output fibers. They play a crucial role...

Optical fiber is a thin, flexible, transparent strand or filament made of glass or plastic used for transmitting light signals over long distances with minimal loss of signal quality. It serves as a...

The amount by which an optical surface deviates from its ideal design value, expressed in wavelengths of light. Optical manufacturers use this value to determine two common characteristics of an...

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...

A piece of glass, pyrex or quartz having one or both surfaces carefully ground and polished plano, generally flat to less than a tenth of a wavelength. Optical flats are used in surface testing to...

The optical Fourier transform is a mathematical operation applied to optical signals that involves transforming a spatial domain representation of an image into its corresponding frequency domain...

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...

Optical glass refers to a type of glass specifically engineered and manufactured for use in optical components and systems, such as lenses, prisms, mirrors, and filters. Optical glass is...

A device for measuring diffraction grating efficiency at any angle of incidence, consisting of a reflectometer wherein the detector rotates around the grating at a specific distance and is attached...

An optical grating, in the context of optics and physics, refers to a device with a periodic structure of closely spaced, parallel slits or rulings. These slits or rulings act as obstacles to the...

In compact disc and CD-ROM technology, the portion of the drive that projects the laser light onto the surface of the media and picks up the resulting reflections read as data. The head includes the...

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

A periodic structure formed by intersecting or superimposed laser beams. These beams can trap atoms in low-potential regions, forming a pattern of atoms resembling the structure of a crystal.

A device used to detect and measure small amounts of rotation. The rotating object contains a reflecting surface from which a beam of light is reflected onto a positional detector. A large distance...

Optical manufacturing tools and machinery encompass a wide range of equipment, instruments, and systems used in the fabrication, shaping, finishing, and testing of optical components and systems....

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...

1. The direct storage of data as bits in memory using optical systems and properties. The memory makes use of a laser beam that is divided by a beamsplitter and controlled by a modulator and a...

Laser-powered telephone device for analog communications that employs a vibrating plastic membrane as a transmitter to modulate laser light piped via optical fibers from a central exchange, omitting...

An instrument that measures several optical parameters, such as optical power and wavelength, with a single measurement input.

Optical noise refers to undesirable fluctuations or disturbances in an optical signal that can affect the quality or integrity of the transmitted information. This type of noise is particularly...

An optical scanning system found in most computer scanners that can read documents, often in many type styles, and convert the document text into digital information to be stored, and displayed by a...

A laser-pumped crystal with nonlinear optical properties inside of an optical resonator in which the output generates coherent light whose output can be tuned continuously over a variety of infrared...

The relative path difference (or phase shift) traveled between two rays that pass through different mediums from the same object point. For a perfect optical system, the optical path, or distance,...

In a medium of constant refractive index, the product of the geometrical distance and the refractive index.

Also known as the Wiener spectrum or the noise power spectrum, the optical power spectrum is a fundamental quantity in film-screen image quality evaluation. It is a means of describing image content...

Also known as a white-light interferometer. Measures surface texture and shape from nanometer-scale roughness to millimeter-scale step heights. A standard arrangement includes an illumination source,...

The process whereby the number of atoms or atomic systems in a set of energy levels is changed by the absorption of light that falls on the material. This process raises the atoms to specific higher...

An instrument for determining the temperature of a hot object by examining the color spectrum of the visible light it gives off and comparing it to the known temperature and wavelength spectrum of...