Definition & Betydelse | Engelska ordet REFRACTION

Definition av REFRACTION

1. (fysik, optik) refraktion

Exempel på hur man kan använda REFRACTION i en mening

• A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction.
• His mentor at the University was Rasmus Bartholin, who published his discovery of the double refraction of a light ray by Iceland spar (a transparent form of the mineral calcite) in 1668, while Rømer was living in his home.
• In optics, the refractive index (or refraction index) of an optical medium is the ratio of the apparent speed of light in the medium to the speed in air or vacuum.
• The refractive index of materials varies with the wavelength of light, and thus the angle of the refraction also varies correspondingly.
• As the angle of incidence approaches a certain threshold, called the critical angle, the angle of refraction approaches 90°, at which the refracted ray becomes parallel to the boundary surface.
• A graded-index fiber, or gradient-index fiber, is an optical fiber whose core has a refractive index that decreases continuously with increasing radial distance from the optical axis of the fiber, as opposed to a step-index fiber, which has a uniform index of refraction in the core, and a lower index in the surrounding cladding.
• In telecommunications, magneto-ionic double refraction is the combined effect of the Earth's magnetic field and atmospheric ionization, whereby a linearly polarized wave entering the ionosphere is split into two components called the ordinary wave and extraordinary wave.
• Causes of multipath include atmospheric ducting, ionospheric reflection and refraction, and reflection from water bodies and terrestrial objects such as mountains and buildings.
• Path loss may be due to many effects, such as free-space loss, refraction, diffraction, reflection, aperture-medium coupling loss, and absorption.
• For example, it is used in optics to calculate the amount of light that is reflected from a surface with a different index of refraction, such as a glass surface, or in an electrical transmission line to calculate how much of the electromagnetic wave is reflected by an impedance discontinuity.
• While a material substance is not required for electromagnetic waves to propagate, such waves are usually affected by the transmission media they pass through, for instance, by absorption or reflection or refraction at the interfaces between media.
• In optics, the law is used in ray tracing to compute the angles of incidence or refraction, and in experimental optics to find the refractive index of a material.
• thumb A mirage is a naturally-occurring optical phenomenon in which light rays bend via refraction to produce a displaced image of distant objects or the sky.
• Anisotropic crystals have double refraction of light where light of different polarizations is bent different amounts by the crystal, and therefore follows different paths through the crystal.
• The catadioptric (combining refraction and reflection) form of the lens, entirely invented by Fresnel, has outer prismatic elements that use total internal reflection as well as refraction to capture more oblique light from the light source and add it to the beam, making it visible at greater distances.
• Rasmus Bartholin is remembered especially for his discovery (1669) of the double refraction of a light ray by Iceland spar (calcite).
• Birch Bay is a headland bay created by the refraction of incoming waves on the headlands that lie on either side of the bay.
• Visibility may vary somewhat with atmospheric refraction; when the air temperature is much greater than the lake temperature, looming may occur where the lake surface or opposing shoreline is lifted above the horizon.
• The fiber-optic effect is the result of the polarization of light into slow and fast rays within each fiber, the internal reflection of the slow ray and the refraction of the fast ray into the slow ray of an adjacent fiber.
• It is transparent to translucent, has high indices of refraction, and ranges from colorless to yellow, green, and dark brown.

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