Photonics Dictionary

The graphed curve illustrating the directional reflectance of a sample for different angles of collection.

The British term for reticle.

An electron tube whose electrical characteristics will not be affected by gaseous ionization because of its high degree of evacuation. Also known as a hard tube.

A plotted relation between Log E (logarithm to base 10 of exposure in metercandle seconds) and density (logarithm to base 10 of opacity).

Any integrated circuit that also makes use of one or more discrete components; frequently used to describe circuits that combine both photonic and electronic components.

Device in which the various circuit elements are fabricated in different substrate materials and then appropriately joined together so that the various substrate materials can be chosen to optimize...

An instrument, similar in design to regular binoculars, that can transmit and enlarge infrared images.

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...

Multiple, interconnected circuit elements, contained on or in a common substrate, that function as a unit and not separately.

An optical circuit, either monolithic or hybrid, composed of active and passive components, used for coupling between optoelectronic devices and providing signal processing functions.

The distance between the two eye pupils when the observer is viewing distant objects (normal = 62 mm).

A lens that is implanted within the eye to replace the eye lens, which has been removed because of cataract or other defect.

Also known as gas focusing. The introduction of an inert gas into a cathode-ray tube for the concentration of the electron beam. The gas molecules are ionized by the electrons, producing a core of...

With respect to the effect of crystals on lightwaves, the family of curves having constant direction of polarization.

Graphic representation of quantified values of image quality whose points all refer to images that are of a constant subjective quality.

The graph of a curve describing the spectral irradiance of extraterrestrial sunlight.

A process used in the design, repair and customization of integrated circuits. A low-power laser etches a silicon wafer placed inside a gas-filled vacuum chamber, initiating a chemical reaction.

An array or mosaic of optical surfaces. May be a number of lenses closely packed to form multiple images or many parallel cylinders used as a projection screen.

A type of additive color photography using a lenticular structure impressed on a film base and a camera lens with a filter having three sectors of red, blue and green. Exposure of the film through...

A method of image dissection whereby a lens transfers images onto a lenticular plate that in turn illustrates the images as structures of narrow parallel lines.

A rear or front projection screen composed of minute optical surfaces that introduce a spread to the light beam that conforms approximately to the light distribution requirements of the application.

A type of stereoscopic photography in which a pair of lenses focuses a pair of images, relative to the positions of the two eyes, onto film through a lenticular screen, which records the images as an...

The stereo image that is recorded by the lenticular, stereo photographic process.

A computer circuit that supplies the action of problem-solving functions or operations.

Plot of spectral luminous efficiency vs. wavelength.

A photometric instrument having two prisms clamped in optical contact to produce a photometric field with an acute dividing line.

The small central portion of the human retina that is responsible for providing the clearest, and most distinct aspects of human vision. Light from an object directly forms an image on the macula...

A vacuum tube in which a magnetic field is superimposed onto the tube's electrical field. When the two fields are aligned, electrons from the photocathode are accelerated through the tube in a spiral...

A theoretical analysis of radiation loss from planar optical waveguides due to scattering by surface irregularities/surface roughness of the walls of the waveguide.

An anastigmatic lens with a thick meniscus construction that flattens the field and corrects chromatic and spherical aberration.

A lens that has one convex surface and the other concave.

An electric arc that is formed in mercury vapor through which an electric current flows. The intensity of the illumination of the arc depends mostly on its design and the conditions under which it...

A lamp that has mercury in a tube or bulb that has first been evacuated. The electricity travels through the vapor between the electrodes and produces a blue-green light that is rich in ultraviolet...

The formation of transistors, diodes, capacitors, resistors and other electronic elements directly on a flake of silicon by etching and selective absorption of doping elements. A circuit diagram...

A method of predicting the nonlinear optical effects exhibited by different molecules without synthesizing the molecules themselves.

A molecular motor refers to a nano-sized device composed of organic molecules or other small-scale components that can convert light energy into mechanical motion at the molecular level. These...

Spectrum analysis concerned with the spectra formed by transitions in molecules.

In a laser diode, the photocurrent produced by a photodiode that detects the emission from the rear facet of the semiconductor chip. It can be used to provide feedback control of the forward current...

1. Viewed with one eye. 2. Describing an image as viewed from a single angle.

Any noise or current fluctuation that prevents precise measurement of the signal current. Both dark current and signal current have random fluctuations that affect the arrival of pulses. Thermal...

The calculated normal distance from a photon source at which harmful interaction with the incident light will occur. Interaction distance produces the effect of MPE (Maximum Permissable Exposure) on...

A plane along which destructive interference takes place.

The physical adaption of the eye lens, by means of ciliary muscle contraction, in order to maintain a clear, in focus image of light and other objects and surroundings at a given distance onto the...