Photonics Dictionary

The series of images formed when periodic objects are exposed to collimated monochromatic radiation and that result from Fresnel diffraction.

A 2D profile sensor is a type of sensor used in various industrial and technological applications to measure and capture detailed information about the shape, contour, or profile of an object in two...

A 3D profile sensor, also known as a 3D profiling sensor or 3D depth sensor, is a technology that is used to capture and measure the three-dimensional shape or profile of an object or a scene. These...

A two-lens arrangement intended to image light into a microscope slide sample. The primary aberrations present are red and blue rings observed around the image focus.

Image of a uniform source through the sample of a microscope image system. Light from the sample plane is reimaged by the objective into the image plane.

A form of roof prism used to invert an image. The prism has faces cut normal to the optical axis; therefore, the prism may be placed within the optical path of a system and invert the image without...

Device which measures the index of refraction of glass as well as the dispersion over visible range.

A reflecting prism that inverts the image. The image is reflected four times internally and emitted laterally. The prism is cut normal to the optical axis while the image is internally reflected from...

A departure from ideal paraxial imaging behavior. The distortion of an optical field wavefront as it is propagated through the elements of an optical system. The field distortion is due to the...

Designed for the function of optical wavefront analysis. Shack-Hartmann camera aberration sensors use a lens array to image the wavefront to the CCD image plane. Live feedback may be applied through...

A doped or absorbing transparent medium cut or molded into a wedge in order to measure the real and imaginary components of the refractive index. An internally reflected Gaussian beam is interfered...

The absorption index represents the imaginary component of the complex index of refraction, and not the real component. The imaginary component may characterize the attenuation per unit length...

The range of angle or solid angle values by which light may enter an optical system.

An achromat, in the context of optics, refers to a type of lens or lens system designed to reduce chromatic aberration. Chromatic aberration is an optical phenomenon where different colors of light...

A lens consisting of two or more elements, usually of crown and flint glass, that has been corrected for chromatic aberration with respect to two selected wavelengths. Also known as achromat.

Cemented prisms of differing refractive indices which refract incident light and, due to differing refractive indices, will not spatially separate individual wavelengths.

The optical reconstruction of image information contained in a sound field. First the diffraction pattern, formed by an object irradiated by ultrasonic rays, interferes with a mutually coherent...

imaging system which clearly shows the IR signals in the field of view as well as ambient environment

In photography, the density gradient across an edge separating light from darkness, a physically measurable quantity that correlates well with subjectively observed sharpness of definition. By...

Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effects of atmospheric distortions. The Earth's atmosphere can cause light passing through it...

A process of color photography in which colors are added one to another in the form of light, rather than as colorants, to obtain color synthesis.

With respect to photography, the change in the density-exposure relations, for small details of the photographic image, that is noted when compared with the density-exposure relations for large...

An aerial reconnaissance system that can transmit, in near real time, image data recorded by IR and visual-spectrum sensors, providing day, night and foul-weather intelligence.

Camera designed for the imaging of the earth's surface in order to obtain high quality aerial images

The creation of a planned sequence of data input that is obtained while airborne for use in aerial photogrammetry and other types of map making and surveying. The data can be photographic, electronic...

The creation of topographical maps and charts from a stereographic record produced through the overlapping of consecutive aerial photographs by more than 50 percent.

Transformation of an image, such as a change in position or scale, that does not alter the linearity of the original image.

An optical system with object and image points at infinity. Literally, "without a focal length."

That image remaining on the detector after the primary stimulus has been removed. In the visual system, the after-image commonly appears as the complementary color of the primary stimulus.

The central peak (including everything interior to the first zero or dark ring) of the focal diffraction pattern of a uniformly irradiated, aberration-free circular optical element or system.

In image processing, the result of a sampling frequency that is too slow to preserve the spatial frequencies of the image. When detail has a frequency greater than half the sampling frequency, it...

In computer imaging, a value representing opacity.

Also known as roof prism. A type of prism designed by G.B. Amici. It consists of a roof edge produced upon the long reflecting face of a right-angle prism. Used as an erecting system in elbow and...

A hologram in which diffraction is produced by the silver image, resulting in a dimmer image than in a phase hologram, where diffraction takes place at the gelatin relief image left once the silver...

An image that can be studied three-dimensionally through a pair of complementary color filters composed of two superimposed views.

A term used to denote a difference in magnification along mutually perpendicular meridians. Anamorphic systems are basically image-distorting systems, such as those used in motion pictures, that...

A lens, usually having one or more cylindrical surfaces, used to produce distorted images and later to restore them to true form.

A state in which an image is distorted by an optical system.

A lens that distorts an optical image.

A compound lens combination whose astigmatic difference is zero for one or more off-axis zones in the image plane. In such a lens the other aberrations are sufficiently well-corrected to yield...

The angle formed between a ray of light striking a surface and the normal to that surface at the point of incidence.