| 释义 |
optical, a. and n.|ˈɒptɪkəl|
[f. prec. + -al1.]
A. adj.
1. Of, pertaining or relating to, the sense of sight; visual; ocular. (Now chiefly in special connexions, e.g. an optical illusion.) Also fig.
In Astron. used of double stars which appear so only because the two components are nearly in the same line of sight, as distinguished from those physically connected (binary).
1570Dee Math. Pref. 20 By demonstration Opticall, the..Cause thereof, is certified. 1723–24Chambers tr. Le Clerc's Treat. Archit. I. 41 The most perfect Arches..consist of a Semicircle; and the Imposts are usually placed on a level with their Centre. There are some Architects, however, who from an Optical consideration, place them a few Minutes lower. 1794[see illusion 4]. c1806D. Wordsworth Jrnl. (1941) I. 253 Right before us..were several small single trees..but some optical delusion had detached them from the land on which they stood, and they had the appearance of..little vessels sailing along the coast of it. 1812Woodhouse Astron. xvii. 184 Divest an observation of any optical or illusory inequality. 1844–57G. Bird Urin. Deposits (ed. 5) 354 This appearance..has always appeared to me to be an optical delusion. 1859Rep. Brit. Assoc. Adv. Sci. 1858 ii. 14 (heading) On an apparatus for exhibiting optical illusions of spectral phenomena. 1868Lockyer Elem. Astron. i. (1879) 20 Optical couples, in which the component stars are really distant from each other, and have no real connection. 1911Rep. Labour & Social Conditions in Germany (Tariff Reform League) III. 193 It may have been an optical illusion, but it certainly did seem to me that Germany was in a state of abounding prosperity. 1922Joyce Ulysses 370 Looks like a phantom ship. No. Wait. Trees are they? An optical illusion. Mirage. 1937K. Blixen Out of Africa v. 386 Between..the mellow English landscape and the African mountain ridge, ran the path of his life: it is an optical illusion that it seemed to..swerve—the surroundings swerved. 1961C. Greenberg Art & Culture 77 Flatness may now monopolize everything, but it is a flatness become so ambiguous and expanded as to turn into illusion itself—at least an optical if not, properly speaking, a pictorial illusion. 1971D. Francis Bonecrack xiii. 169 Don't be tempted by the optical illusion that the winning post is much nearer than it really is. 1976Times 20 Feb. 14/4 But it will be said, surely the growth of public spending has..been arrested... Not, alas, so. This is an optical illusion.
2. a. Of or pertaining to sight in relation to the physical action of light upon the eye; hence, Pertaining or relating to light, as the medium of sight, or generally in relation to its physical properties; belonging to optics. Also used with specific reference to visible light as contrasted with other electromagnetic radiation; spec. operating in or employing the visible part of the spectrum.
optical axis = optic axis (see optic A. 5). optical centre, that point in the axis of a lens so situated that all rays passing through it remain unrefracted. optical density, (a) the degree in which a refractive medium retards transmitted rays of light; (b) the logarithm to the base 10 of the opacity.
1570Dee Math. Pref. 48 The chief Science of the Arche⁓master..is an other (as it were) Optical Science. 1663Boyle Usef. Exp. Nat. Philos. i. 96 An eye thus frozen, may be cut along that which Optical Writers call the Optical Axis, and then it affords an instructive Prospect. 1736Butler Anal. i. i. 29 Common optical Experiments. 1831Brewster Optics ii. §23. 16 The image..cannot be used for any optical purpose. 1869Tyndall Notes Lect. Light §117 Hence the all-important optical law: ‘the sine of the angle of incidence divided by the sine of the angle of refraction is a constant quantity’. 1891W. Abney in Jrnl. Soc. Chem. Industry 31 Jan. 20/1 From the colour of the negatives..the photographic and optical densities were very nearly alike. 1953J. W. T. Walsh Photometry (ed. 2) v. 161 The reciprocal of the transmission factor of a plate is sometimes termed the opacity of the plate and the logarithm to base 10 of the opacity is often known as the optical density of the plate. 1958, etc. [see maser]. 1960[see laser2 1]. 1966S. D. Rockoff in G. D. Whedon et al. Progress in Devel. of Methods in Bone Densitometry 7/1 The mean optical density of the bone, obtained from densitometric scanning of the radiographic image of the bone is expressed in terms of thickness of calibration wedge material which gives the same optical density. 1967Listener 27 Apr. 544/2 Before the radio telescope made its impact..the optical telescopes were able to photograph galaxies. 1970Sci. Jrnl. Mar. 14 The first machine to automate completely one of the important processes of optical astronomy. 1974McGraw-Hill Yearbk. Sci. & Technol. 11/2 The VLA will allow scientists to see, study, and map the radio sky at wavelengths of 1 cm or greater, with detail even greater than that possible for earthbound optical telescopes.
b. Used with reference to electromagnetic radiation other than light, and to beams of particles analogous to light: relating to the transmission of such radiation.
1933[see electron-optical adj. s.v. electron2 2 b]. 1938Maloff & Epstein Electron Optics in Television i. 38 The electron optical problem of the electron microscope is to obtain electrostatic or magnetostatic lenses of short focal lengths capable of producing high magnifications with low image distortions. 1944R. A. Sawyer Exper. Spectroscopy xi. 277 Infrared spectroradiometers differ from those used in the ultraviolet, or visible, regions chiefly because of the optical characteristics of the infrared region. 1964Jrnl. Optical Soc. Amer. LIV. 15/2 A recent study of optical properties in the extreme ultraviolet.
c. Designating a form of abstract art and visual decoration in which optical effects are used to provide illusions of movement in the patterns produced. Chiefly as optical art, optical artist, optical painting, etc. Abbrev. op4. orig. U.S.
1964Time 23 Oct. 78/1 Preying and playing on the fallibility in vision is the new movement of ‘optical art’ that has sprung up across the Western world. 1964Life 11 Dec. 133 Op-art is short for ‘optical art’, a paradoxical movement dedicated to the practice of fascinating deceptions. 1965Reporter (N.Y.) 14 Jan. 46/3 They [sc. Israeli artists] do have the beginnings of Pop Art and Op Art (Optical Art). 1965Listener 4 Feb. 196/3 To pass..to the American optical painter Edward Avedisian, and thence to the British Patrick Caulfield, is to realize the impossibility to trying to apply consistent standards to modern art. 1965Observer 28 Feb. 2/6 The occasion was the private viewing of the most important show of the New York art season—an exhibition called ‘The Responsive Eye’, which has gathered together, for the first time, a comprehensive international collection of optical art. 1965New Scientist 20 May 491 Leaving aside the question of the contemporary fashion for ‘optical’ painting, Vasarely's work shows—indeed it largely created—two important trends in abstract art today. 1968N. Weston Kaleidoscope of Mod. Art xv. 220 The public has taken to Optical art in a big way, and it has spread rapidly from the art galleries to the Press. 1969Time 7 Feb. 4 The Manhattan optical artist [sc. Josef Levi] has devised several new dizzying exercises with illuminated shadow boxes superimposed on black and white perforated metal screens. 1969New Yorker 1 Nov. 12/3 Optical paintings by a leading Latin-American artist. 1970C. Barrett Op Art i. 7/1 The evolution of abstract art was a preliminary step towards the development of optical painting. 1973J. Lancaster Introducing Op Art ii. 28 Optical art is a method of painting concerning the interaction between illusion and picture plane, between understanding and seeing.
3. Treating of, or skilled in, optics.
1570Dee Math. Pref. 48 The Astronomer, and the Opticall Mechanicien. 1605Camden Rem. 203 Pecham that Opticall Archbishop of Canterbury who writte Perspectiva Communis. 1704Norris Ideal World ii. vii. 359 So..we are told by the optical men. 1815D. Stewart Dissert. Progr. Philos. i. ii. (1858) 132 The various signs of it, enumerated by optical writers.
4. Constructed to assist the sight, or to enable one to see objects otherwise invisible; acting by means of sight or light; devised on the principles of optics. optical square: see quot. 1875.
1610H. Wotton Let. 13 Mar. in L. P. Smith Life & Lett. Sir H. Wotton (1907) I. 486 The Mathematical Professor at Padua, who by help of an optical instrument..hath discovered four new planets. a1666Evelyn Diary an. 1641 (1955) II. 64 Those spotts in the Moone, attributed to the seas there &c according to our new Philosophy & the Phænomenas by optical Glasses. 1748Lady Luxborough Lett. to Shenstone 17 Apr., It would give me pain to see St. James's, Vauxhall, Ranelagh &c. &c., represented in so lively a manner as I see them through an optical glass, which I have lately purchased, now that I am absent from them. 1839G. Bird Nat. Philos. 381 Description of Optical Apparatus, and of the Eye considered as an Optical Instrument. 1875Knight Dict. Mech., Optical Square, a reflecting instrument used by surveyors and others for laying off lines at right angles to each other. Ibid., Optical Telegraph, a semaphoric telegraph. One whose signals are formed by altering the relative position of its indicators or by differing combinations of colors. 1891Anthony's Photogr. Bull. IV. 100 Nothing has done more to popularize the optical lantern, or magic lantern, as it is more commonly called, than the introduction of mineral oil lamps.
5. optical bleach, optical brightener, optical white: a substance applied to textiles which produces a whitening effect by absorbing ultraviolet light and re-emitting it as blue light; so optical bleaching, optical brightening, optical whitening.
1947Jrnl. Textile Inst. XXXVIII. A 521 ‘Optical bleaching’ is defined as the physical alteration of a white fabric in such a way as to make it reflect, in addition to white light, a certain amount of blue light, and thereby producing a much ‘bluer’ and also brighter white than before. 1948Amer. Dyestuff Reporter XXXVII. 432/3 Whereas ‘bluings’ improve the appearance of white products by absorbing red light, and ‘bleaches’ improve their appearance by destroying the yellow color, ‘optical bleaches’ operate on the entirely different principle of transforming ultra-violet and violet radiation into visible blue light. 1959Which? Sept. 107/2 If a detergent with optical white is used on a white fabric too generously or too often, the fabric can get a blue or mauve tint which is not particularly pleasing. 1961Cohen & Linton Chem. & Textiles for Laundry Industry v. 79 Optical bleaches will give blue by light emission and consequently improve brightness both psychologically and actually—that is, a ‘whiter’ white is obtained. 1964Kirk & Othmer Encycl. Chem. Technol. (ed. 2) III. 739 The principle of optical bleaching was described in 1929 by Krais, but the industrial use of optical brightening began about ten years later. 1964Ibid. XIX. 13 The majority of optical brighteners that are commercially available are based on stilbene derivatives. 1971A. K. Sarkar Fluorescent Whitening Agents i. 1 Fluorescent whitening agents are known under various names, e.g. optical whitening agents, optical bleaching agents or optical bleaches, fluorescent bleaching agents, whiteners, brighteners, etc. 1974Encycl. Brit. Macropædia XVI. 916/2 Now an integral part of all washing powders, optical brighteners are dye⁓stuffs absorbed by textile fibres from solution but not subsequently removed in rinsing. Ibid., The chemical structures of optical brightening agents are complicated.
6. Special collocations: optical activity, the ability of a substance to produce optical rotation; optical axis, centre: see sense 2; optical bench, a straight, rigid bar, usu. graduated, along which supports for lenses, light sources, and the like can be slid and to which they can be clamped; optical character reader, a device which performs optical character recognition and produces coded signals corresponding to the characters identified; optical character recognition, identification of printed characters using photoelectric devices; optical comparator, an instrument for facilitating comparisons of two objects by projecting shadows or transparencies of them on to a screen; optical disc Computing, a smooth non-magnetic disc with a special coating that allows data to be recorded on it by means of a laser beam and read by a laser scanner, providing a large storage capacity; optical fibre, a fibre that will act as a light guide in fibre optics; optical flat (see flat n.3 2 f); optical glass, glass of specially high homogeneity manufactured for use in optical components (see also sense 4); optical isomer, each of two isomeric compounds whose molecules are enantiomorphs and which are distinguishable by their equal but opposite optical rotations; so optical isomerism; † optical length = optical path below; optical model Nuclear Physics, a model of the atomic nucleus in which it is treated as having a potential well with an additional negative imaginary component, so that its behaviour with respect to incident particles is somewhat analogous to that of a partially absorbing body with respect to incident light waves; optical path, the distance which in a vacuum would contain the same number of wavelengths as the actual path followed by a ray of light, equal to the product of the actual path-length and the refractive index of the medium if the latter is homogeneous; optical printer = projection printer s.v. projection 10; optical pumping [tr. F. pompage optique (A. Kastler 1950, in Jrnl. de Physique et la Radium XI. 257/2)], the production of an inversion in the population of certain energy levels in the atoms of a gas by the absorption of optical (visible) resonance radiation of suitable polarization; optical pyrometer, a device for measuring the temperature of an incandescent body by comparing its brightness with that of a heated filament in the instrument; optical rotation, the rotation of the plane of polarization of plane-polarized light by a substance through which it passes; spec. = specific rotation; optical scanner = optical character reader above; optical scanning, scanning in which the light reflected or transmitted by the area being scanned is detected, esp. as used in optical character recognition; optical sound Cinemat., sound recorded by optical (photographic) means on a film.
1877Chem. News 23 Nov. 230/1 The optical activity disappears in those derivatives of active bodies, by the formation of which the so-called asymonetry [sic] of the carbon atoms ceases. 1883Athenæum 29 Dec. 871/1 A series of sugars, having the composition of C6H12O6, is formed, of gradually decreasing optical activity, which the author names α, β, γ, and δ arabinose. 1967K. B. Krauskopf Introd. Geochem. xi. 295 If a natural material containing carbon compounds can be shown to possess optical activity, the conclusion seems inescapable that living organisms played a role in its formation.
1883R. T. Glazebrook Physical Optics v. 113 The experiment is usually made on an optical bench. 1974Sci. Amer. Apr. 28/3 An optical laboratory needs a large optical bench that is typically 20 feet long.
1962Proc. Symposium Optical Character Recognition i. 133 The IBM 1418 Optical Character Reader..provides an example of the maximum tolerance for several of these variables that can be obtained in today's commercially available character readers. 1968Amer. Documentation Jan. 74/2 Typed pages are transferred to magnetic tape by an optical character reader. 1974Encycl. Brit. Macropædia XIV. 892/1 The U.S. Post Office has had an alpha-numeric optical character reader in operation on live mail since 1965.
1962Proc. Symposium Optical Character Recognition i. 93 A research and development program was initiated..to create a wide-tolerance optical character recognition system. 1970O. Dopping Computers & Data Processing iii. 64 In optical character recognition (OCR), the reader responds to the darkness of the ink, just as the human eye does.
1935O. W. Boston Engin. Shop Pract. II. ix. 452 An optical comparator or Optimeter is a gage used for comparing the size of various parts with that of master gages. 1967Economist 14 Oct. 4 (Advt. suppl. following p. 176), The image of the gauge, magnified to 50 times its size, is projected on the screen of the Optical Comparator so that the finest details of the thread can be examined and checked. 1976M. Maguire Scratchproof iii. 40 Perhaps the boys at forensic had made a gaff. Perhaps the optical comparator was malfunctioning.
1977Computer & Information Syst. XVII. 514/1 The objective of the program is to develop an inexpensive optical disk recorder suitable for minicomputer applications. 1981New Scientist 29 Oct. 310 One optical disc can store up to 200 million bytes of information. 1985Personal Computer World Feb. 196/3 The optical disk is 12in in diameter, double-sided, and its tracks are made up of a series of micron-sized pits illuminated by a low-power, helium-neon laser. These are read by a photodiode.
1970Sci. Jrnl. Dec. 68 Nobody has yet produced glass which meets all the challenging requirements of optical fibres. 1974McGraw-Hill Yearbk. Sci. & Technol. 27/1 Optical fibers that act as ‘light pipes’ have been around for some years, serving in a variety of ways—in medical instruments, in photocopying machines, in automobile instrument panels.
1840Mem. R. Astron. Soc. XI. 165 (heading) On the optical glass prepared by the late Dr. Ritchie. 1879Encycl. Brit. X. 665/1 Optical glass is of two principal kinds—flint and crown. 1922L. Bell Telescope iii. 60 The fundamental difference between the making of optical glass and the ordinary commercial varieties lies in the individual treatment of each charge necessary to secure uniformity and regularity. 1973D. G. Holloway Physical Prop. Glass iv. 107 The characteristics of optical glasses are customarily represented by quoting the refractive index for one of the sodium D lines and the constringence.
1892Optical isomer [see enantiomorph]. 1974Encycl. Brit. Macropædia V. 138/2 Optical isomers differ from the other isomeric coordination compounds in that their physical and chemical properties are identical.
1894Jrnl. Chem. Soc. LXVI. i. 422 (heading) Optical isomerism of closed chain compounds. 1968R. O. C. Norman Princ. Org. Synthesis v. 156 Optical isomerism in biphenyls is possible because the conformation..which possesses a plane of symmetry is strained with respect to non-coplanar conformations.
1894Phil. Mag. XXXVII. 515 The time it takes for an impulse at G to pass completely through F will be that required by light to go over a space equal to the difference in optical length of the extreme rays GBF and GAF. 1934W. H. A. Fincham Optics ii. 26, nl is termed the optical length of a path l in medium of refractive index n.
1952Le Levier & Saxon in Physical Rev. LXXXVII. 40/1 There is an energy range for which the problem of nucleon-nuclei scattering is somewhat analogous to the scattering of light by a conducting glass sphere... Such a medium is conventionally described by introducing a complex index of refraction... We have investigated an optical model for nucleon-nuclei scattering in which a complex square well potential is used, this being equivalent to a complex index of refraction. 1963P. E. Hodgson Optical Model Elast. Scattering i. 3 The initial development of the optical model was due to Fernbach, Serber, and Taylor (1949). 1970I. E. McCarthy Nuclear Reactions i. iii. 70 A mechanistic description of a non-elastic reaction..involves an optical model description of the system while it is in the entrance channel and another one while it is in the exit channel. The transition between these channels is described by a model which includes details of nuclear structure.
1893Phil. Mag. XXXV. 471 The phenomenon is due to the interference of two parallel gratings... Their distance, which is virtually constant, is the optical path, 2ne, e being the thickness, and n the index of the gelatine. 1923Glazebrook Dict. Applied Physics IV. 216/1 The differences of optical paths are a direct measure of the distortion from true spherical form of the waves emerging from a lens system. 1957G. E. Hutchinson Treat. Limnol. I. vi. 391 Poole and Atkins computed b, the mean optical path per meter, as 1·19.
1944Jrnl. Soc. Motion Pict. Engin. XLII. 204 The use of the optical printer to enhance the value of the modern motion picture is demanded increasingly by studios with foresight enough to give a free hand to the man in charge of the optical department. 1953L. J. Wheeler Princ. Cinematogr. v. 144 Figure 61 shows in outline the layout of the intermittent or ‘stop’ optical printer. 1974L. Lipton Independent Filmmaking i. 39 Optical printers are used to make dissolves, special effects, frame line corrections, freeze-frame printing and so on. The optical printer is also ideal for the preparation of master printing material printed from original camera film.
1952Physical Rev. LXXXV. 1051/2 The net result is an optical ‘pumping’ as Kastler suggests, from m = - ½ to m = + ½ , or a tendency in the direction of nuclear orientation. This is in competition with a disorienting tendency caused by collisions. 1959[see multilevel a.]. 1970G. K. Woodgate Elem. Atomic Struct. ix. 191 Recently..the methods of optical pumping, double resonance, and level-crossing spectroscopy have begun to provide data on the hyperfine structure of excited states.
1901G. K. Burgess tr. Le Chatelier & Boudouard's High-Temperature Measurements viii. 155 The optical pyrometer, by reason of the uncertainty of emissive powers.., cannot give as accurate results as other pyrometric methods. 1922Glazebrook Dict. Appl. Physics I. 649/1 It is possible to calibrate optical pyrometers by direct observations of freezing- or melting-points. 1958Bussard & DeLauer Nuclear Rocket Propulsion viii. 303 The optical pyrometer has been built around the frequency-response characteristics of the human eye.
1895C. S. Palmer tr. Nernst's Theoret. Chem. ii. v. 288 The connection with constitution is shown in no other physical property so clearly as it is in this of optical rotation. 1929R. A. Gortner Outl. Biochem. xxi. 473 Naturally-occurring tartaric acid is the d form, and its purity is usually determined by the optical rotation of a solution of the acid. 1967Oceanogr. & Marine Biol. V. 190 Suzuki and Suzuki..have demonstrated that ovalbumin has an optical rotation of - 27·6° in the native state.
1962Proc. Symposium Optical Character Recognition i. 16 (caption) An example of the actual printed output which optical scanners are required to read. 1975McGraw-Hill Yearbk. Sci. & Technol. 201/1 An optical scanner..reads a symbol printed on the product as it is passed over a slit in the checkout counter.
1958J. Moir High Quality Sound Reproduction xviii. 540 Optical scanning of the sound track takes place while the film is held in contact with the drum and rotating with it. 1971Computers & Humanities V. 282 Optical scanning of printed texts (avoiding the need for keypunching the material).
[1933B. Brown Amat. Talking Pict. vii. 146 The optical sound system of the R.C.A. portable is shown diagrammatically.] 1960McGraw-Hill Encycl. Sci. & Technol. III. 124/2 The magnetic sound track is..26 frames ahead [of the picture] on 16-mm film, the same as optical sound. 1970New Yorker 29 Aug. 22/1 Here we have to use optical sound—printed down the side of the film.
B. n.
1. Cinematogr. and Television. (See quots.)
1953K. Reisz Technique Film Editing 281 Optical, any device carried out by the optical department of a laboratory requiring the use of the optical printer, e.g., dissolve, fade, wipe. 1959Halas & Manvell Technique Film Animation 340 Opticals, mixes, fades, wipes, etc., which are made by the processing laboratories on an optical printing machine after the scenes have been photographed, instead of in the camera during photography. 1959Punch 28 Oct. 366/2 Many amateurs are clearly of the opinion that this [sc. the subject matter] is of minor importance, their chief concern being to demonstrate their skill at devising star-burst wipes and other trick opticals. 1969C. O. Raspor in W. R. R. Park Plastics Film Technol. iv. 94 It has become customary to distinguish three properties of films which are generally categorized as ‘opticals’: gloss, haze, and transparency. 1970A. Fowles Dupe Negative xiv. 192 ‘I've got four hundred feet of 35 mm. ECO original here,’ I said, ‘how long will it take to strike a master positive?’.. ‘You can have it by five this evening,’ he said, ‘but wouldn't you rather have an optical?’ 1974L. Lipton Independent Filmmaking vi. 273 When printed with an optical printer, the image can have the same orientation as it had on the camera film. If we used a contact printer to make the fades and dissolves, and then cut them into the master, we'd wind up with release prints with flopped opticals.
2. An example of optical art.
1966New Statesman 5 Aug. 208/2 A sizzling red-blue optical by Ellsworth Kelly.
Add:[A.] [4.] b. Computing. Designating (a part of) a computer requiring infrared, visible, or ultraviolet radiation for its operation, spec. as a means of storing or retrieving data, or (usu. in coherent form) as a substitute for electric current in some experimental systems. See also optical character reader, recognition, optical disc, scanner, sense 6 below.
1947Ann. Computation Lab. Harvard Univ. XVI. 147 Optical and photographic storage methods are applicable to the supplementary and permanent storage problems. These methods are called optical in that optical means are used in conjunction with mechanical scanning for switching the data into and out of storage. 1959Jrnl. Optical Soc. Amer. XLIX. 1012 Examples of optical methods of calculation are described, and the construction of an optical analog computer for synthesizing the two-dimensional fourier transform of a function for use in crystal structure determination is described. 1965Electronics 6 Sept. 72/1 Optical analog computers have been in use for several years, but they have really come of age with the laser. An optical computer powered by a laser can multiply a 10,000-element vector by a 10,000 x 10,000 matrix in one millisecond. 1971New Scientist 8 July 80/2 Although most of the big companies can build optical memories in the laboratory, they still say they are a long way from turning out optical computers on the production line. 1980C. S. French Computer Sci. xxix. 237 Chain printers or optical paper tape reader[s] make transfers of data at rates which correspond to dozens or hundreds of instructions. 1988Fortune 1 Feb. 58/3 The optical computer, using laser beams instead of electrical connections, would work 1,000 times faster than today's electronic variety. |