Total external reflection
- Total external reflection
Total external reflection is an optical phenomenon where electromagnetic radiation (e.g. visible light) can, at certain angles, be "totally" reflected from an interface between two media of different indices of refraction (see Snell's law). Total internal reflection occurs when the first medium has a larger refractive index than the second medium, for example, light that emerges from under water. The optically denser material (water in this case) is the "internal" medium. For visible light, water has an index of refraction of 1.33 and for air it is very close to 1. For vacuum the index of refraction is exactly 1 for all wavelengths.
For X-rays, however, all materials have indices of refraction slightly below 1. This entails that total reflection of X-rays only can occur when they travel through vacuum and impinge on a surface (at a small glancing angle). Since this kind of total reflection takes place outside of the material it is termed "total external reflection".
Wikimedia Foundation.
2010.
Look at other dictionaries:
total external reflection — visiškasis išorės atspindys statusas T sritis fizika atitikmenys: angl. total external reflection vok. äußere Totalreflexion, f rus. полное внешнее отражение, n pranc. réflexion totale externe, f … Fizikos terminų žodynas
Total internal reflection — The larger the angle to the normal, the smaller is the fraction of light transmitted, until the angle when total internal reflection (blue line) occurs. (The color of the rays is to help distinguish the rays, and is not meant to indicate any… … Wikipedia
Total internal reflection fluorescence microscope — (TIRFM) diagram 1. Specimen 2. Evanescent wave range 3. Cover slip 4. Immersion oil 5. Objective 6. Emission beam (signal) 7. Excitation beam ] 1. Objective 2. Emission beam (signal) 3. Immersion oil 4. Cover slip 5. Specimen 6. Evanescent wave… … Wikipedia
Reflection (physics) — Reflection is the change in direction of a wave front at an between two different media so that the wave front returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves. Law of… … Wikipedia
Total S.A. — Total S.A. Type Société Anonyme Traded as Euronext: FP, NYSE: … Wikipedia
Reflection (mathematics) — This article is about reflection in geometry. For reflexivity of binary relations, see reflexive relation. A reflection through an axis followed by a reflection across a second axis parallel to the first one results in a total motion which is a… … Wikipedia
Ai no Melody/Chōwa Oto (With Reflection) — Single by Kokia from the album Pearl: The Best Collection Released … Wikipedia
Refractive index — Refraction of light at the interface between two media. In optics the refractive index or index of refraction of a substance or medium is a measure of the speed of light in that medium. It is expressed as a ratio of the speed of light in vacuum… … Wikipedia
Photon — This article is about the elementary particle of light. For other uses, see Photon (disambiguation). Photon Photons emitted in a coherent beam from a laser Composition Elementary particle … Wikipedia
Microstructured optical arrays — (MOAs) are instruments for focusing x rays. MOAs utilise total external reflection at grazing incidence from an array of small channels in order to bring x rays to a common focus. This method of focusing means that MOAs exhibit low absorption.… … Wikipedia
