Photonics Dictionary

A filtering method that restores a blurred image by setting its power spectrum equal to that of the original image.

In remote sensing technology, this represents the intensity of energy flow in the direction of wave propagation.

A transition boundary between two regions having different properties in a P-type semiconducting material.

Ratio of the molecular diffusion coefficients of momentum in terms of heat; used in convection studies.

An accurately produced hole of any size and shape that is used as a masking device in an optical system. Pinhole apertures of accurate diameters often are produced by laser beam penetration or by...

A step before fusion splicing that involves cleaning the fiber end with low-current electricity.

A method of determining prism power at any point on a lens. Prism power equals the product of the dioptric power and the distance, in centimeters, from the optical center.

A state in which the human eye has very little or no power of accommodation. A common and normal condition in the eyes of those age 50 and older.

A blank having basic surface curves attained by forming heat-softened glass that is pressed in a mold.

Injecting a gas (usually nitrogen) with a very low moisture content into the body of an optical instrument to create a positive internal pressure. This prevents the entrance of moisture, which could...

In a waveguide, the material in intimate contact with the cladding surface, applied to preserve the integrity of that surface.

A set of three colored lights which, when mixed, give the sensation of white light. The set used in color television, for example, is red, green, blue (RGB).

Fluorescence produced as a result of the intrinsic property of the material itself or the doping of the material with trace elements.

A straight line connecting the curvature centers of the refracting lens surfaces. In a mechanical sense, a line joining the centers of a lens as it is placed in a mount. The principal axis is the...

In a lens or lens system, that surface at which the projections of an entering and exiting ray intersect. Also known as the equivalent refracting surface, the principal plane is most often not...

The intersection of the principal plane and the optical axis of a lens.

The ray of an oblique pencil beam that passes through the center of the pupils. It is the effective axis of the oblique beam. Also called the chief ray.

The thin edge of a refracting prism; the line of intersection of two refracting surfaces of a prism.

A pair of telescopes with prismatically erected images, mounted side by side with the eyepieces at the interocular distance of the observer. This separation is adjustable with a convenient millimeter...

The chromatic resolving power of a prism is invariably stated for the case in which parallel rays of light are incident on the prism, in which the prism is oriented at the angle of minimum deviation...

An instrument that measures the angle at which a prism can couple laser light into an optical waveguide; used to determine the thickness and refractive index of thin films in integrated optical...

The power, expressed in prism diopters, that is the linear displacement, in centimeters, produced by the prism one meter away.

A prism is a geometric optical element with flat, polished surfaces that refract light. It is typically a solid, transparent object with at least two flat surfaces that are inclined relative to each...

The spectrum formed by a dispersing prism or a dispersing prism system.

Acronym for profile resolution obtained by excitation. In its simplest form, probe involves the overlap of two counter-propagating laser pulses of appropriate wavelength, such that one pulse...

A probe card is a testing device used in the semiconductor manufacturing industry to evaluate and test the electrical characteristics of integrated circuits (ICs) on a wafer. Its primary function is...

The collection and analysis of data relevant to monitoring the rate and quality of industrial production, either continuously or in batches. Corrections can be made manually or automatically, via a...

A lens that is symmetrical and designed to work between 1:1 and about 4:1. It covers a field of about ±20° at f/8 or f/10, and may have a focal length up to about 30 in., although the usual...

A superposition of many zone plates, each reconstructing a real and virtual point image at the appropriate locations upon illumination by a reference beam.

In an optical waveguide, that dispersion attributable to the variation of refractive index profile with wavelength. The profile variation has two contributing factors: variation in refractive index...

Measurement of surface roughness or quality through the use of a diamond-pointed stylus connected to a coil in an electric field. As the stylus is traced across the surface, a current is created that...

In computerized industrial process control, the element that determines the choice and sequence of operations dependent on varying conditions.

A contour mapping technique that involves projection of a grating onto an object to produce a shadow grating that is observed through another grating. Therefore, the size of the object to be measured...

The measurement of surface temperature by a thermograph that forms a pattern of the heat radiated by the surface on a luminescent screen.

The minimum amount of strength characteristic of an optical fiber, as determined by proof stressing; expressed in thousands of pounds of pressure per square inch.

A means of testing the strength of optical fibers to ensure reliability, by applying stress to the fiber so that any flaws generated during manufacturing or handling result in breakage of the fiber.

For an electromagnetic field mode varying sinusoidally with time at a given frequency, the logarithmic rate of change, with respect to distance in a given direction, of the complex amplitude of any...

Technique using a fiber optic assembly to illuminate an opaque object and transmit an image back from it without a lens system on the distal end.

A noncontact sensor used in the remote measurement of position, speed or other variables of moving parts.