…a line passing through the centre of curvature of a lens or spherical mirror and parallel to the axis of symmetry…
…a straight rigid bar, typically marked with a scale, to which supports for lenses, light sources, and other optical components can be attached…
…the distance which in a vacuum would contain the same number of wavelengths as the actual path taken by a ray of light…
…relating to or employing both optical and magnetic phenomena or technology…
…the degree to which a refractive medium retards transmitted rays of light…
…a group of two stars which appear to constitute a double star due to their being in the same line of sight as seen from the earth, but are actually at different distances…
…each of two or more forms of a compound which have the same structure but are mirror images of each other and typically differ in optical activity…
…a device which performs optical character recognition and produces coded signals corresponding to the characters identified…
…the property (displayed by solutions of some compounds, notably many sugars) of rotating the plane of polarization of plane-polarized light…
…a fluorescent substance added to detergents in order to produce a whitening effect on laundry…
…something that deceives the eye by appearing to be other than it is…
…a microscope using visible light, typically viewed directly by the eye…
…the rotation of the plane of polarization of plane-polarized light by an optically active substance…
…an access control system without barriers in which those attempting to enter are evaluated by closed-circuit television or other visual means…
…a device that uses light from a low-wattage laser to manipulate individual molecules within cells…
…the identification of printed characters using photoelectric devices and computer software…
…an information storage device for a computer in the shape of a round flat plate which can be rotated to give access to all parts of the surface. The data may be stored either magnetically (in a magnetic disk) or optically (in an optical disk such as a CD-ROM)…
…a form of abstract art that gives the illusion of movement by the precise use of pattern and colour, or in which conflicting patterns emerge and overlap. Bridget Riley and Victor Vasarely are its most famous exponents…
…an imaginary ellipsoidal surface whose axes represent the refractive indices of a crystal for light following different directions with respect to the crystal axes…
…an information storage device for a computer in the shape of a round flat plate which can be rotated to give access to all parts of the surface. The data may be stored either magnetically (in a magnetic disk) or optically (in an optical disk such as a CD-ROM)…
…an imaginary ellipsoidal surface whose axes represent the refractive indices of a crystal for light following different directions with respect to the crystal axes…
