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Dichroic Filter, Dichroic
In optics, a dichroic material is either one which causes visible light to be split up into distinct beams of different wavelengths (colours) (not to be confused with dispersion), or one in which light rays having different polarizations are absorbed by different amounts. In beam splitters The original meaning of ''dichroic'', from the Greek ''dikhroos'', two-coloured, refers to any optical device which can split a beam of light into two beams with differing wavelengths. Such devices include mirrors and filters, usually treated with optical coatings, which are designed to reflect light over a certain range of wavelengths and transmit light which is outside that range. An example is the dichroic prism, used in some camcorders, which uses several coatings to split light into red, green and blue components for recording on separate CCD arrays, however it is now more common to have a Bayer filter to filter individual pixels on a single CCD array. This kind of dichroic device does n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circular Dichroism
Circular dichroism (CD) is dichroism involving circular polarization, circularly polarized light, i.e., the differential Absorption (electromagnetic radiation), absorption of left- and right-handed light. Left-hand circular (LHC) and right-hand circular (RHC) polarized light represent two possible spin angular momentum of light, spin angular momentum states for a photon, and so circular dichroism is also referred to as dichroism for spin angular momentum. This phenomenon was discovered by Jean-Baptiste Biot, Augustin Fresnel, and Aimé Cotton in the first half of the 19th century. Circular dichroism and optical rotation, circular birefringence are manifestations of optical activity. It is exhibited in the absorption (electromagnetic radiation), absorption bands of optical activity, optically active chirality (chemistry), chiral molecules. CD spectroscopy has a wide range of applications in many different fields. Most notably, Ultraviolet, far-UV CD is used to investigate the second ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid Crystals
Liquid crystal (LC) is a state of matter whose properties are between those of conventional liquids and those of solid crystals. For example, a liquid crystal can flow like a liquid, but its molecules may be oriented in a common direction as in a solid. There are many types of LC phases, which can be distinguished by their optical properties (such as textures). The contrasting textures arise due to molecules within one area of material ("domain") being oriented in the same direction but different areas having different orientations. An LC material may not always be in an LC state of matter (just as water may be ice or water vapour). Liquid crystals can be divided into three main types: thermotropic, lyotropic, and metallotropic. Thermotropic and lyotropic liquid crystals consist mostly of organic molecules, although a few minerals are also known. Thermotropic LCs exhibit a phase transition into the LC phase as temperature changes. Lyotropic LCs exhibit phase transitions a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polaroid (polarizer)
Polaroid is a type of synthetic plastic sheet which is used as a polarizer or polarizing filter. A trademark of the Polaroid Corporation, the term has since entered common use. Patent The original material, patented in 1929 and further developed in 1932 by Edwin H. Land, consists of many microscopic crystals of iodoquinine sulphate (herapathite) embedded in a transparent nitrocellulose polymer film. The needle-like crystals are aligned during the manufacture of the film by stretching or by applying electric or magnetic fields. With the crystals aligned, the sheet is dichroic: it tends to absorb light which is polarized parallel to the direction of crystal alignment but to transmit light which is polarized perpendicular to it. The resultant electric field of an electromagnetic wave (such as light) determines its polarization. If the wave interacts with a line of crystals as in a sheet of polaroid, any varying electric field in the direction parallel to the line of the crystals wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herapathite
Herapathite, or iodoquinine sulfate, is a chemical compound whose crystals are dichroic and thus can be used for polarizing light. Its formation was investigated by 1852 by William Bird Herapath, a Bristol surgeon and chemist, after his pupil (Mr. W. H. Phelps) was attracted by some peculiarly brilliant emerald-green crystals that he noticed in a bottle containing a large quantity of the mixed disulfates of quinine and cinchonine. Herapath found that he could create these crystals by dropping tincture of iodine into a solution of quinine disulfate in diluted sulfuric acid and that, by studying the crystals under a microscope, that they polarized light very strongly. The story that a dog was involved in the discovery can be found in the widely quoted publication /sup>. There appears to be no reliable evidence for it other than the article, nearly one hundred years later by E. H. Land. In the 1930s, invented a process to grow single herapathite crystals large enough to be sandwi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Minerals'; p. 1. In the series ''Geology: Landforms, Minerals, and Rocks''. Rosen Publishing Group. The Geology, geological definition of mineral normally excludes compounds that occur only in living organisms. However, some minerals are often biogenic (such as calcite) or organic compounds in the sense of chemistry (such as mellite). Moreover, living organisms often synthesize inorganic minerals (such as hydroxylapatite) that also occur in rocks. The concept of mineral is distinct from rock (geology), rock, which is any bulk solid geologic material that is relatively homogeneous at a large enough scale. A rock may consist of one type of mineral or may be an aggregate (geology), aggregate of two or more different types of minerals, spaci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineralogy
Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their utilization. History Early writing on mineralogy, especially on gemstones, comes from ancient Babylonia, the ancient Greco-Roman world, ancient and medieval History of China, China, and Sanskrit texts from History of India, ancient India and the ancient Islamic world. Books on the subject included the ''Naturalis Historia, Natural History'' of Pliny the Elder, which not only described many different minerals but also explained many of their properties, and Kitab al Jawahir (Book of Precious Stones) by Persian scientist Al-Biruni. The German Renaissance specialist Georgius Agricola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterling Publishing Company, Inc
Sterling may refer to: Currency * The English penny, historically known as the ''sterling'' * Pound sterling, the currency of the United Kingdom * Sterling silver, a grade of silver Places United Kingdom * Stirling, a Scottish city whose alternative historical spelling is ''Sterling'' United States * Sterling, Alaska * Sterling, Colorado * Sterling Micropolitan Statistical Area, Colorado * Sterling, Connecticut * Sterling, Georgia * Sterling, in Bingham County, Idaho * Sterling Wildlife Management Area, Idaho * Sterling, Illinois * Sterling, a ghost town in Jackson County, Iowa * Sterling, Kansas * Sterling, Massachusetts * Sterling, Michigan * Sterling Heights, Michigan * Sterling State Park, Michigan * Sterling Center, Minnesota * Sterling, Missouri * Sterling, in Madison County, Montana * Sterling, Nebraska * Sterling, New York * Sterling, in Mecklenburg County, North Carolina * Mount Sterling (Great Smoky Mountains), North Carolina * Sterling, North Dakota * Ster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleochroism
Pleochroism is an optical phenomenon in which a substance has different colors when observed at different angles, especially with Polarization (waves), polarized light. Etymology The roots of the word are from Greek (). It was first made compound in the German term ''Pleochroismus'' by mineralogist Wilhelm Haidinger in 1854, in the journal ''Annalen der Physik und Chemie''. Its first known English usage is by geologist James Dana in 1854. Background Anisotropy, Anisotropic crystals will have optical properties that vary with the direction of light. The direction of the electric field determines the polarization of light, and crystals will respond in different ways if this angle is changed. These kinds of crystals have one or two optical axes. If absorption of light varies with the angle relative to the optical axis in a crystal then pleochroism results. Anisotropic crystals have double refraction of light where light of different Polarization (waves), polarizations is bent di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tourmaline
Tourmaline ( ) is a crystalline silicate mineral, silicate mineral group in which boron is chemical compound, compounded with chemical element, elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. This gemstone comes in a wide variety of colors. The name is derived from the Sinhala language, Sinhalese (), which refers to the carnelian gemstones. History Brightly colored Ceylonese gem tourmalines were brought to Europe in great quantities by the Dutch East India Company to satisfy a demand for curiosities and gems. Tourmaline was sometimes called the "Ceylonese Magnet" because it could attract and then repel hot ashes due to its Pyroelectricity, pyroelectric properties. Tourmalines were used by chemists in the 19th century to Polarization (waves), polarize light by shining rays onto a cut and polished surface of the gem. Species and varieties Commonly encountered species and varieties of tourmaline include the following: * Schorl species ** Brownish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macroscopic single crystals are usually identifiable by their geometrical shape, consisting of flat faces with specific, characteristic orientations. The scientific study of crystals and crystal formation is known as crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification. The word ''crystal'' derives from the Ancient Greek word (), meaning both "ice" and " rock crystal", from (), "icy cold, frost". Examples of large crystals include snowflakes, diamonds, and table salt. Most inorganic solids are not crystals but polycrystals, i.e. many microscopic crystals fused together into a single solid. Polycrystals include most metals, rocks, ceramics, and ice. A third cat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Mechanics
Quantum mechanics is the fundamental physical Scientific theory, theory that describes the behavior of matter and of light; its unusual characteristics typically occur at and below the scale of atoms. Reprinted, Addison-Wesley, 1989, It is the foundation of all quantum physics, which includes quantum chemistry, quantum field theory, quantum technology, and quantum information science. Quantum mechanics can describe many systems that classical physics cannot. Classical physics can describe many aspects of nature at an ordinary (macroscopic and Microscopic scale, (optical) microscopic) scale, but is not sufficient for describing them at very small submicroscopic (atomic and subatomic) scales. Classical mechanics can be derived from quantum mechanics as an approximation that is valid at ordinary scales. Quantum systems have Bound state, bound states that are Quantization (physics), quantized to Discrete mathematics, discrete values of energy, momentum, angular momentum, and ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
