n. (Astron.) an optical system used in some telescopes since the 1980's which rapidly changes the shape of the primary reflecting mirror to adjust for distortions of light which are caused by atmospheric turbulence. By reducing the distortions caused by the atmosphere, telescopes fitted with such optics can achieve a higher resolving power than normal telescopes with static mirrors. [ PJC ]
n. that branch of optics which studies the transmission of light through thin transparent fibers. Light transmission through optical fibers has become an important means of data and telephone signal transmission, in some areas superseding the carrying of vioce and data signals through electrical pulses over copper wire. It is also used for directly carrying images from otherwise inaccessible locations, as from inside the body, for medical procedures. Light transmission via fiber optics for data transmission uses an optical fiber made of specially purified glass with low light absorption characteristics. [ PJC ]
n. [ Hetero- + optics. ] False optics. Spectator. [ 1913 Webster ]
n. [ Cf. F. optique, L. optice, Gr. &unr_; (sc. &unr_;). See Optic. ] That branch of physical science which treats of the nature and properties of light, the laws of its modification by opaque and transparent bodies, and the phenomena of vision. [ 1913 Webster ]
n. The art or process of exhibiting luminous images, especially those of external objects, in a darkened room, by arrangements of lenses or mirrors. [ 1913 Webster ]