This page gathers the 130 dictionary entries belonging to the domain “Optics”, as labelled by Wiktionary. Each word leads to its full entry: definitions, etymology, pronunciation, examples. Page 1 of 2: from “aa” to “pantoscopic”.
- aa noun Initialism of angular aperture.
- aberration noun The convergence to different foci, by a lens or mirror, of rays of light emanating from one and the same point, or the deviation of such…
- absorptance noun Absorbed radiation and incident radiation in a ratio format; a measurement that shows how well a surface absorbs radiation.
- acceptance noun Synonym of etendue.
- accidental colour noun A colour depending on the hypersensibility of the retina of the eye for complementary colours. They are purely subjective sensations of…
- achromat noun A lens that imparts little color; a lens that is achromatic.
- achromatic adj Free from color; transmitting light without color-related distortion.
- achromatic lens noun A lens generally composed of two separate lenses, one convex and one concave and generally of different materials, in such a way that the…
- achromatism noun The state or quality of being achromatic; achromaticity.
- adaptive optics noun An optical system in telescopes that reduces atmospheric distortion by dynamically measuring and correcting wavefront aberrations in real…
- afocal adj Not focused
- Airy disk noun The bright central region of the diffraction pattern resulting from a uniformly illuminated circular aperture.
- albedo noun The fraction of incident light or radiation reflected by a surface or body, commonly expressed as a percentage.
- analyzer noun a type of polarizer
- angle of incidence noun The angle that a straight line, ray of light, etc., meeting a surface, makes with a normal to the surface at the point of meeting.
- aperture noun A hole which restricts the diameter of the lightpath through one plane in an optical system.
- aplanat noun A lens that has been corrected for spherical aberration and coma in order to produce a rectilinear image.
- astigmatism noun A defect of a lens such that light rays coming from a point do not meet at a focal point so that the image is blurred.
- axial point noun nodal point
- barlow noun A Barlow lens.
- Barlow lens noun A diverging lens which, used in series with other optics in an optical system, increases the effective focal length of an optical system as…
- bifocal adj Having two focal lengths.
- brewster noun A unit of stress optical coefficient which is equal to 10⁻¹² m²/N or 10⁻¹² Pa⁻¹. Symbol: B.
- catadioptric adj Of or pertaining to optical systems that employ both reflective (catoptric) and refractive (dioptric) elements.
- caustic noun The envelope of reflected or refracted rays of light for a given surface or object.
- caustic curve noun A curve to which the ray of light, reflected or refracted by another curve, are tangents, the reflecting or refracting curve and the…
- Christiansen effect noun The reduced scattering of multi-phase microstructures at wavelengths where their refractive indices match.
- Christiansen filter noun A narrow bandpass or monochromatic optical filter which consists of an optical cell which is filled with a crushed substance (e.g. glass)…
- chromatic adj Having the capacity to separate spectral colours by refraction.
- chromatic aberration noun An optical aberration in which an image has coloured fringes, caused by differential refraction of light of different wavelengths.
- chromatics noun The science of colours; the branch of optics that deals with the properties of colours.
- chromatism noun chromatic aberration
- circle of confusion noun An optical spot caused by a cone of light rays from a lens not coming to a perfect focus when imaging a point source.
- coma noun A defect characterized by diffuse, pear-shaped images that in an ideal image would appear as points.
- comatic adj Of or pertaining to coma (the distortion of a lens).
- complement noun The color which, when mixed with the given color, gives black (for mixing pigments) or white (for mixing light).
- condenser noun A lens (or combination of lenses) designed to gather light and focus it onto a specimen or part of a mechanism.
- confocal adj Having the same foci.
- conformal optics noun A method of designing optical systems in which the conformation of the lenses is chosen to optimize its interaction with the local…
- constringence noun A measure of a material's dispersion (variation of refractive index with wavelength) in relation to the refractive index.
- convex lens noun A lens having at least one convex surface, such that light passing through it may be brought to a focus.
- correlator noun A type of device used to compare two signals
- corrugated lens noun A type of lens where concentric portions are cut out from the surface to lessen the weight without affecting the focal power.
- critical angle noun The angle of incidence beyond which light traveling through a medium experiences total internal reflection upon encountering a boundary…
- crown glass noun A variety of glass used in lenses and other optical components due to its low refractive index and dispersion. Originally crown glass was…
- Dawes resolution limit noun A criterion for a telescope's resolving power, representing the minimum angular separation between two stars that a human observer can…
- decentre verb To place away from the centre; to make eccentric.
- defocus noun The distance by which the focal point is in front of (positive defocus) or beyond (negative defocus) the image or target surface.
- delay line noun A mechanical or optical system used to compensate for the differences in optical path lengths of light beams originating from individual…
- diaphragm verb To reduce lens aperture using an optical diaphragm.
- diascopic adj Describing an optical device in which light traverses (rather than being reflected by) the object being observed.
- dichromatic adj having two hues, either of which may be visible depending on both the concentration of the absorbing substance and the depth or thickness…
- diffuser noun Any device that or spreads out or scatters light, making the light appear softer.
- distortion noun An aberration that causes magnification to change over the field of view.
- eikonometer noun An instrument for determining the magnifying power of a microscope
- episcopic adj Describing an optical device in which light is reflected by (rather than traversing) the object being observed
- etendue noun A conserved property of the light in an optical system which characterizes how "spread out" the light is in terms of angle and area: it is…
- ferroelectric shutter noun A shutter consisting of a slab of ferroelectric crystal located between polarizers whose planes are at right angles
- field lens noun a positive-powered lens or group of lenses that comes after the objective lens and before the image plane or the eyepiece, serving to…
- field of view noun The angular extent of what can be seen, either with the eye or with an optical instrument or camera.
- field stop noun The aperture that limits the field of view of a lens.
- flat noun A flat (i.e. plane) mirror
- focal depth noun The field of view of a camera that is in sharp focus.
- focal length noun A measure of how strongly an optical system converges or diverges light, the inverse of optical power. In the simple case of a single…
- focal plane noun Any plane perpendicular to the axis of a lens or mirror.
- focal point noun A focus; a point at which rays of light or other radiation converge.
- focalization noun The act or practice of putting into focus.
- focus noun A point at which reflected or refracted rays of light converge.
- Fresnel number noun A dimensionless quantity (denoted F), such that for an electromagnetic wave passing through an aperture and hitting a screen, F=(a²)/(Lλ)…
- Gaussian beam noun A beam of electromagnetic radiation with high monochromaticity whose amplitude envelope in the transverse plane is given by a Gaussian…
- Glan–Thompson prism noun A polarizing prism similar to the Glan–Foucault prism, except the air gap is replaced with a layer of cement.
- glistening noun A fluid-filled microvacuole within a lens.
- glory noun An optical phenomenon, consisting of concentric rings and somewhat similar to a rainbow, caused by sunlight or moonlight interacting with…
- graticule noun Synonym of reticle (“a transparent plate marked with a crosshair, grid, or scale which is used in an optical instrument, etc., to aid in…
- half-silvered mirror noun A mirror that consists of an incomplete reflective coating, so that half of the incident light is reflected and the other half is…
- high-powered adj Of an instrument, capable of great magnification.
- hot spot noun Synonym of heiligenschein (“an optical phenomenon which creates a bright spot around the shadow of the viewer's head, when the surface on…
- hubble noun A space telescope or spy satellite with a design like the Hubble Space Telescope.
- hyperlens noun A nanostructured metamaterial that produces magnified images of objects smaller than the wavelength of the light used
- image noun The collection of focus points of light rays coming from a given object.
- integration time noun The duration of time in which a sensor collects and accumulates incoming light or signals.
- intensity noun Any of radiant intensity, luminous intensity or irradiance.
- isochromatic adj Having the same colour or wavelength.
- lens noun An object, usually made of glass, that focuses or defocuses the light that passes through it.
- Littrow prism noun A retroreflecting dispersing prism arranged so that an incident light beam entering at Brewster's angle undergoes minimal deviation and…
- low-powered adj Of an instrument, capable of minimal magnification.
- luminance noun The luminous flux emitted in a given direction divided by the product of the projected area of the source element perpendicular to the…
- magneto-optic effect noun The property changes (i.e. polarization, spectrum, phase, intensity) in an electromagnetic wave when it propagates through a medium that…
- meniscus noun A lens which is convex on one side and concave on the other, being crescent-shaped in cross-section.
- microdoublet noun A doublet lens (typically composed of a solid lens and a liquid-filled lens) made by microfabrication
- misfigure noun The misfigured portion of an optical surface, or the presence of such a portion.
- monocentric noun A monocentric lens.
- monogon noun A single-faceted reflector.
- motion parallax noun The illusion of higher speed travel of a foreground object moving, when it is closer to the observer/camera, than when it is further away.
- negative crystal noun A uniaxial crystal, such as one of calcite, in which the extraordinary wave travels faster than the ordinary wave
- opacity noun A measure of relative impenetrability to electromagnetic radiation such as light.
- optic adj Of, or relating to optics or optical instruments.
- optical flat noun A disk of high-quality quartz glass having at least one side ground and polished with a deviation in flatness less than 50 nanometers all…
- overfogged adj Having a focal point that is in front of the retina or observer; myopic.
- pantoscopic adj Designed to focus on both near and distant objects at the same time, typically by means of a tilt in the lens