Photonics Dictionary: A

An autocollimator is an optical instrument used for measuring small angular deviations with high precision. It operates on the principle of autocollimation, where a light source is directed onto a...

Automated optical inspection (AOI) is a technology used in manufacturing processes, particularly in electronics, to automatically inspect and detect defects or anomalies in products. AOI systems use...

A system for automatic industrial process control or measurement, consisting of an optical module for image acquisition, a segmentation processor to isolate the image from its background, and an...

In fiber optics, the use of a detector to study the range of refractive indices achieved at various wavelengths. This information is calculated electronically to establish the divergence between...

A low-power telescope placed at the eyepiece of an optical system to increase overall magnification. Most often used to evaluate image quality.

A receiver for optical communications systems consisting of a symmetric binary, pulse-code-modulated transmitter, a log-normal channel and an array of independent photocounting detectors that yield...

In astronomy, the method of deliberately viewing objects with peripheral vision to take advantage of the eye's greater sensitivity to faint light a few degrees from the optical center.

A bundle of rays that originates from an object point on the optical axis of a lens system.

In gradient index optics, a gradient profile in which the refractive index varies along the direction of light propagation, or optical axis. Axial gradient lenses can be used to correct spherical...

A paraxial light ray that extends from an object point on the optical axis.

A vapor-phase oxidation process for fabricating graded-index optical fibers. It differs from outside vapor phase deposition in that the preform is developed radially rather than longitudinally. An...

An optical device that produces a line image lying along the axis from a point source of light; therefore, it has no definite focal length. A lens with a weak conical surface on one face.

A straight line, real or imaginary, passing through a body and indicating its center; a line so positioned that various portions of an object are located symmetrically in relation to the line. See...

Azimuthal polarization refers to a specific polarization state of light where the electric field vector of the electromagnetic wave points along the azimuthal direction (around the propagation axis)....