| 释义 |
Brewster2 Physics.|ˈbruːstə(r)|
[The name of the Scottish physicist Sir David Brewster (1781–1868).]
1. Used attrib. in connection with his discoveries in optics, as Brewster('s) angle, the angle of incidence at the surface of a dielectric for which a wave polarized in the plane of incidence is not reflected at all, and an unpolarized wave is reflected as a plane-polarized one; Brewster('s) fringes (or bands), interference fringes produced when a beam of (white or monochromatic) light passes through two sheets of glass, etc., and undergoes different internal reflections in them; Brewster's law [published by Brewster in 1815], the law that the tangent of the Brewster angle is equal to the refractive index of the dielectric (in a vacuum), or to the ratio of the refractive indices of the media either side of the interface; Brewster window, a window in a laser, etc., so arranged as to polarize light by reflection at the Brewster angle.
[1932Hardy & Perrin Princ. Optics xxix. 600 The angle of incidence for which the polarization of the transmitted light is a maximum is somewhat less than the Brewsterian angle.] 1950Jenkins & White Fund. Optics (ed. 2) xxiv. 489 The physical reason why light vibrating in the plane of incidence is not reflected at *Brewster's angle lies in the transverse character of light vibrations. 1962Corson & Lorrain Introd. Electromagn. Fields xi. 369 For light incident on glass with an index of refraction of 1·6, the Brewster angle is about 58°. 1980Sci. Amer. Oct. 178/1 Because of the Brewster angle, however, one type of polarization is enhanced, and it quickly comes to dominate the laser process. 1984D. C. Giancoli Gen. Physics xxxviii. 736 At Brewster's angle, the reflected and transmitted rays make a 90° angle to each other.
1890T. Preston Theory of Light viii. 156 (heading) *Brewster's bands.
1934Discovery July 185/2 A group of straight and parallel interference fringes (known as *Brewster's fringes) is seen through the telescope, the group consisting of a central white fringe accompanied by a few coloured fringes on either side. 1963R. W. Ditchburn Light (ed. 2) ix. 359 The Brewster fringes..are observed by means of M1. 1976Jenkins & White Fund. Optics (ed. 4) xiv. 303 The usefulness of Brewster's fringes lies chiefly in the fact that when they appear, the ratio of the two interferometer spacings is very exactly a whole number.
1882Encycl. Brit. XIV. 611 (heading) *Brewster's law. 1937Jenkins & White Fund. Optics xiv. 316 This is Brewster's law, which shows that the angle of maximum polarization depends on the refractive index and therefore varies with wave-length. 1973R. S. Longhurst Geom. & Physical Optics (ed. 3) xxi. 519 If the angle of incidence for light in one direction is the polarizing angle and the directions of the incident and refracted rays are reversed, the new angle of incidence is the polarizing angle for light in the reverse direction. This follows at once from the original statement of Brewster's law.
[1962Rev. Sci. Instruments XXXIII. 921 (heading) Construction of a gaseous optical maser using Brewster angle windows.] 1965Appl. Phys. Lett. VII. 244/1 In the present work a *Brewster window tube with external mirrors was used. 1984Nat. Geographic Mar. 341 (caption) In some gas lasers transparent disks called Brewster windows.., slanted at a precise angle, polarize the laser's light.
2. (With lower-case initial.) A unit of measurement for the stress-optical coefficient of a material, equal to 10-12 m2N-1 (orig. 10-10 cm2 per gramme force, equal to (10-12/0.981) m2N-1).
1910L. N. G. Filon in Proc. R. Soc. A. LXXXIII. 576 The stress-optical coefficients..are expressed in a unit of 10-10 cm.2 per gramme weight. It would be very desirable to have a short name for this unit{ddd}I propose to call it a brewster. 1938Jrnl. R. Aeronaut. Soc. XLII. 570 The stress-optical coefficient of a certain soft vulcanised rubber compound is found to be 2,030 brewsters. 1980L. Levi Appl. Optics II. x. 11 The difference in refractive index parallel and normal to the stress direction is readily calculated by the formula Δn = SB = 10-12 S*B* where S is the stress (S* when in units of N/m2) and B is the stress-optic coefficient (sometimes called Brewster's constant) of the material (B* when in units of brewsters, i.e., reciprocal pN/m2).
Hence Brewˈsterian a.
1942Ann. Reg. 1941 355 An explanation of the elliptical polarisation of light reflected at the Brewsterian angle which is independent of the existence of surface films or strains in the refracting medium. 1963R. W. Ditchburn Light (ed. 2) xii. 545 With most surfaces, the light reflected at the Brewsterian angle is elliptically polarized. |