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Deformable Mirror
Deformable mirrors (DM) are mirrors whose surface can be deformed, in order to achieve wavefront control and correction of optical aberrations. Deformable mirrors are used in combination with wavefront sensors and real-time control systems in adaptive optics. In 2006 they found a new use in femtosecond pulse shaping. The shape of a DM can be controlled with a speed that is appropriate for compensation of dynamic aberrations present in the optical system. In practice the DM shape should be changed much faster than the process to be corrected, as the correction process, even for a static aberration, may take several iterations. A DM usually has many degrees of freedom. Typically, these degrees of freedom are associated with the mechanical actuators and it can be roughly taken that one actuator corresponds to one degree of freedom. Deformable mirror parameters Number of actuators determines the number of degrees of freedom (wavefront inflections) the mirror can correct. It is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
E-ELT
The Extremely Large Telescope (ELT) is an astronomical observatory currently under construction. When completed, it is planned to be the world's largest optical/near-infrared extremely large telescope. Part of the European Southern Observatory (ESO) agency, it is located on top of Cerro Armazones in the Atacama Desert of northern Chile. The design consists of a reflecting telescope with a segmented primary mirror and a diameter secondary mirror, and will be supported by adaptive optics, eight laser guide star units and multiple large science instruments. The observatory aims to gather 100 million times more light than the human eye, 13 times more light than the largest optical telescopes existing in 2014, and be able to correct for atmospheric distortion. It has around 256 times the light gathering area of the Hubble Space Telescope and, according to the ELT's specifications, would provide images 16 times sharper than those from Hubble. The project was originally called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wavefront Sensor
In physics, the wavefront of a time-varying ''wave field'' is the set (locus) of all points having the same '' phase''. The term is generally meaningful only for fields that, at each point, vary sinusoidally in time with a single temporal frequency (otherwise the phase is not well defined). Wavefronts usually move with time. For waves propagating in a unidimensional medium, the wavefronts are usually single points; they are curves in a two dimensional medium, and surfaces in a three-dimensional one. For a sinusoidal plane wave, the wavefronts are planes perpendicular to the direction of propagation, that move in that direction together with the wave. For a sinusoidal spherical wave, the wavefronts are spherical surfaces that expand with it. If the speed of propagation is different at different points of a wavefront, the shape and/or orientation of the wavefronts may change by refraction. In particular, lenses can change the shape of optical wavefronts from planar to sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CILAS
CILAS is a French company, a subsidiary of Ariane Group, specialized in laser and optics technology, founded in 1966. This high-technology engineering company was the inventor of the particle size analyzer. Today, it develops, manufactures and produces systems combining laser and precision optics in the field of high technology, accounting. Products for the military represent 50% of turnover against 50% civilian. History This company was founded in 1966 by two companies : CGE (Compagnie Generale d'Électricité becoming Alcatel-Alsthom) and Saint-Gobain. The aim was to exploit industrially and commercially the work of laboratories working on laser sources and laser equipment. In 1983, it became CILAS-Alcatel. In 1985, it was absorbed by two companies of optics : SORO Electro-Optics and BBT (Barbier Bernard and Turenne). Alcatel Alcatel may refer to: * Alcatel, a former French telecommunications equipment company, which became Alcatel-Lucent and is now part of Nokia * Alca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boston Micromachines Corporation
Boston Micromachines Corporation is a US company operating out of Cambridge, Massachusetts. Boston Micromachines manufactures and develops instruments based on MEMS technology to perform open and closed-loop adaptive optics. The technology is applied in astronomy, beam shaping, vision science, retinal imaging, microscopy, laser communications, and national defense. The instruments developed at Boston Micromachines include deformable mirrors, optical modulators, and retinal imaging systems, all of which utilize adaptive optics technology to enable wavefront manipulation capabilities which enhance the quality of the final image. History Founded in 1999 by Dr. Thomas Bifano and Paul Bierden, Boston Micromachines is a provider of MEMS-based mirror products for use in commercial adaptive optics systems which apply wavefront correction to produce high resolution images of the human retina and enhance blurred images. The company also performs contract research in optical MEMS fabrica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ALPAO
ALPAO is a company which manufactures a range of adaptive optics products for use in research and industry, including deformable mirrors with large strokes, wavefront sensors, and adaptive optics loops. These products are designed for astronomy, vision science, microscopy, wireless optical communications, and laser applications. History ALPAO developed from groundwork at the Université Joseph Fourier (Grenoble) and Floralis. In 2006 and 2008 ALPAO received awards for innovative technology from the French Ministry of Research. Other ALPAO partners include the Institut de Planétologie et d'Astrophysique de Grenoble, OSEO, ANR, Région Rhône-Alpes, Grenoble Alpes Incubation, the Reseau Entreprendre and Business France. * 2017 ALPAO signs major contracts to supply Observatoire de Paris with a state-of-the-art high order DM, Physical Sciences Inc. with DM's for retinal imagers, ESO's Very Large Telescope Interferometer array for adaptive optics upgrade of the auxiliary telesco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferrofluid Mirror
A ferrofluid mirror is a type of deformable mirror with a reflective liquid surface, commonly used in adaptive optics. It is made of ferrofluid and magnetic iron particles in ethylene glycol, the basis of automotive antifreeze. The ferrofluid mirror changes shape instantly when a magnetic field is applied. As the ferromagnetic particles align with the magnetic field, the liquid becomes magnetized and its surface acquires a shape governed by the equilibrium between the magnetic, gravitational and surface tension forces. Since any shapes can be produced by changing the magnetic field geometries, wavefront control and correction can be achieved. A ferrofluid mirror is controlled by a number of actuators, often arranged in a hexagonal array. Pure ferrofluids have low reflectivity, so they must be coated with a reflective layer. Water-based ferrofluids hold the reflective layer effectively, but water evaporates so quickly that the mirror could disappear within hours. Depositing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferrofluid
Ferrofluid is a liquid that is attracted to the poles of a magnet. It is a colloidal liquid made of nanoscale ferromagnetic or ferrimagnetic particles suspended in a carrier fluid (usually an organic solvent or water). Each magnetic particle is thoroughly coated with a surfactant to inhibit clumping. Large ferromagnetic particles can be ripped out of the homogeneous colloidal mixture, forming a separate clump of magnetic dust when exposed to strong magnetic fields. The magnetic attraction of tiny nanoparticles is weak enough that the surfactant's Van der Waals force is sufficient to prevent magnetic clumping or agglomeration. Ferrofluids usually do not retain magnetization in the absence of an externally applied field and thus are often classified as "superparamagnets" rather than ferromagnets. In contrast to ferrofluids, magnetorheological fluids (MR fluids) are magnetic fluids with larger particles. That is, a ferrofluid contains primarily nanoparticles, while an MR fluid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferrofluid Deformable Mirror
Ferrofluid is a liquid that is attracted to the poles of a magnet. It is a colloidal liquid made of nanoscale ferromagnetic or ferrimagnetic particles suspended in a carrier fluid (usually an organic solvent or water). Each magnetic particle is thoroughly coated with a surfactant to inhibit clumping. Large ferromagnetic particles can be ripped out of the homogeneous colloidal mixture, forming a separate clump of magnetic dust when exposed to strong magnetic fields. The magnetic attraction of tiny nanoparticles is weak enough that the surfactant's Van der Waals force is sufficient to prevent magnetic clumping or agglomeration. Ferrofluids usually do not retain magnetization in the absence of an externally applied field and thus are often classified as "superparamagnets" rather than ferromagnets. In contrast to ferrofluids, magnetorheological fluids (MR fluids) are magnetic fluids with larger particles. That is, a ferrofluid contains primarily nanoparticles, while an MR f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Economies Of Scale
In microeconomics, economies of scale are the cost advantages that enterprises obtain due to their scale of operation, and are typically measured by the amount of output produced per unit of time. A decrease in cost per unit of output enables an increase in scale. At the basis of economies of scale, there may be technical, statistical, organizational or related factors to the degree of market control. This is just a partial description of the concept. Economies of scale apply to a variety of the organizational and business situations and at various levels, such as a production, plant or an entire enterprise. When average costs start falling as output increases, then economies of scale occur. Some economies of scale, such as capital cost of manufacturing facilities and friction loss of transportation and industrial equipment, have a physical or engineering basis. The economic concept dates back to Adam Smith and the idea of obtaining larger production returns through the use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MEMS Magnetic Actuator
A MEMS magnetic actuator is a device that uses the microelectromechanical systems (MEMS) to convert an electric current into a mechanical output by employing the well-known Lorentz Force Equation or the theory of Magnetism. Overview of MEMS Micro-Electro-Mechanical System (MEMS) technology is a process technology in which mechanical and electro-mechanical devices or structures are constructed using special micro-fabrication techniques. These techniques include: bulk micro-machining, surface micro-machining, LIGA, wafer bonding, etc. A device is considered to be a MEMS device if it satisfies the following: * If its feature size is between 0.1 µm and hundreds of micrometers. (below this range, it becomes a nano device and above the range, it is considered a mesosystem) * If it has some electrical functionality in its operation. This could include the generation of voltage by electromagnetic induction, by changing the gap between 2 electrodes or by a piezoelectric material ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
