Photonics Dictionary

A support for optical parts comprising a solid bed that permits precise longitudinal movement of one component relative to the others, and a number of sliders equipped with holders for lenses, lamps,...

The phenomenon that can render an optical resonator the equivalent of a semiconductor flip-flop. A bistable device will remain stable in two optical states, one of high transmission and another of...

A light absorbing material applied to ground optical surfaces during the process of making that surface non reflective. Such material should have a refractive index as high as that of the underlying...

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 mechanical or electrical-electromagnetic device for periodically interrupting or blocking abeam of light for a brief known interval. The three most common chopper types include the tuning fork...

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 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,...

A dome-shaped structure used for some optical instruments in place of a flat window. The transparent material should be of good quality and the hemispherical surfaces should be concentric.

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...

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...

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...

A support for optical parts comprising a solid bed that permits precise longitudinal movement of one component relative to the others, and a number of sliders equipped with holders for lenses, lamps,...

A mechanical or electrical-electromagnetic device for periodically interrupting or blocking abeam of light for a brief known interval. The three most common chopper types include the tuning fork...

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...

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

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

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...

The determination of the temperature of a source by the detection of its incandescent brightness.

A support for optical parts comprising a solid bed that permits precise longitudinal movement of one component relative to the others, and a number of sliders equipped with holders for lenses, lamps,...

In an optical fiber or waveguide communications system, an optoelectronic device or module that receives an optical signal, converts this optical signal to an electrical signal which is then...

With respect to microscopy, also called dispersive staining, optical staining the projection of colors through areas of a colorless specimen by color filters that are constructed to fit over the...

The element that resembles a lightweight metal, but when very pure, has a very high electrical resistance and is transparent to the infrared between about 0.5 and 15 µm.

1.) Generally, the electromagnetic spectrum within the wavelength region extending from the vacuum ultraviolet at 40 nm to the far-infrared at 1 mm. 2.) The wavelength or color distribution...

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,...

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...

The area of optics that deals with the propagation of Gaussian laser beams in free space, or any general medium - i.e. lenses- under the paraxial (small divergence angle) approximations. Gaussian...

A type of erasable data storage device that uses a medium deposited on the disc in two layers, each dyed to absorb a different wavelength of laser light. To record data, the lower layer is heated by...