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Coherent Perfect Absorber
A coherent perfect absorber (CPA), or anti-laser, is a device which absorbs coherent light and converts it to some form of internal energy such as heat or electrical energy. It is the time-reversed counterpart of a laser. The concept was first published in the July 26, 2010, issue of ''Physical Review Letters'', by a team at Yale University led by theorist A. Douglas Stone and experimental physicist Hui W. Cao. In the September 9, 2010, issue of ''Physical Review A'', Stefano Longhi of Polytechnic University of Milan showed how to combine a laser and an anti-laser in a single device. In February 2011 the team at Yale built the first working anti-laser. It is a two-channel CPA device which absorbs the output of two lasers, but only when the beams have the correct phases and amplitudes. The initial device absorbed 99.4 percent of all incoming light, but the team behind the invention believe it will be possible to achieve 99.999 percent. Originally with the FP cavity, the optical CPA o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coherent Light
In physics, two wave sources are coherent if their frequency and waveform are identical. Coherence is an ideal property of waves that enables stationary (i.e., temporally or spatially constant) interference. It contains several distinct concepts, which are limiting cases that never quite occur in reality but allow an understanding of the physics of waves, and has become a very important concept in quantum physics. More generally, coherence describes all properties of the correlation between physical quantities of a single wave, or between several waves or wave packets. Interference is the addition, in the mathematical sense, of wave functions. A single wave can interfere with itself, but this is still an addition of two waves (see Young's slits experiment). Constructive or destructive interference are limit cases, and two waves always interfere, even if the result of the addition is complicated or not remarkable. When interfering, two waves can add together to create a wave of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time-reversal Symmetry
T-symmetry or time reversal symmetry is the theoretical symmetry of physical laws under the transformation of time reversal, : T: t \mapsto -t. Since the second law of thermodynamics states that entropy increases as time flows toward the future, in general, the macroscopic universe does not show symmetry under time reversal. In other words, time is said to be non-symmetric, or asymmetric, except for special equilibrium states when the second law of thermodynamics predicts the time symmetry to hold. However, quantum noninvasive measurements are predicted to violate time symmetry even in equilibrium, contrary to their classical counterparts, although this has not yet been experimentally confirmed. Time ''asymmetries'' generally are caused by one of three categories: # intrinsic to the dynamic physical law (e.g., for the weak force) # due to the initial conditions of the universe (e.g., for the second law of thermodynamics) # due to measurements (e.g., for the noninvasive measure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light which is coherence (physics), ''coherent''. Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and Photolithography#Light sources, lithography. Spatial coherence also allows a laser beam to stay narrow over great distances (collimated light, collimation), enabling applications such as laser pointers and lidar (light detection and ranging). Lasers can also have high temporal coherence, which allows them to emit light with a very narrow frequency spectrum, spectru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Review Letters
''Physical Review Letters'' (''PRL''), established in 1958, is a peer-reviewed, scientific journal that is published 52 times per year by the American Physical Society. As also confirmed by various measurement standards, which include the '' Journal Citation Reports'' impact factor and the journal ''h''-index proposed by Google Scholar, many physicists and other scientists consider ''Physical Review Letters'' to be one of the most prestigious journals in the field of physics. ''According to Google Scholar, PRL is the journal with the 9th journal h-index among all scientific journals'' ''PRL'' is published as a print journal, and is in electronic format, online and CD-ROM. Its focus is rapid dissemination of significant, or notable, results of fundamental research on all topics related to all fields of physics. This is accomplished by rapid publication of short reports, called "Letters". Papers are published and available electronically one article at a time. When published ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yale University
Yale University is a Private university, private research university in New Haven, Connecticut. Established in 1701 as the Collegiate School, it is the List of Colonial Colleges, third-oldest institution of higher education in the United States and among the most prestigious in the world. It is a member of the Ivy League. Chartered by the Connecticut Colony, the Collegiate School was established in 1701 by clergy to educate Congregationalism in the United States, Congregational ministers before moving to New Haven in 1716. Originally restricted to theology and sacred languages, the curriculum began to incorporate humanities and sciences by the time of the American Revolution. In the 19th century, the college expanded into graduate and professional instruction, awarding the first Doctor of Philosophy, PhD in the United States in 1861 and organizing as a university in 1887. Yale's faculty and student populations grew after 1890 with rapid expansion of the physical campus and sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hui W
The Hui people ( zh, c=, p=Huízú, w=Hui2-tsu2, Xiao'erjing: , dng, Хуэйзў, ) are an East Asian ethnoreligious group predominantly composed of Chinese-speaking adherents of Islam. They are distributed throughout China, mainly in the northwestern provinces and in the Zhongyuan region. According to the 2011 census, China is home to approximately 10.5 million Hui people. The 110,000 Dungan people of Kazakhstan and Kyrgyzstan are also considered part of the Hui ethnicity. The Hui have a distinct connection with Islamic culture. For example, they follow Islamic dietary laws and reject the consumption of pork, the most commonly consumed meat in China, and have developed their own variation of Chinese cuisine. They also dress differently than the Han Chinese, some men wear white caps ( taqiyah) and some women wear headscarves, as is the case in many Islamic cultures. The Hui people are one of 56 ethnic groups recognized by China. The government defines the Hui peopl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Review A
''Physical Review A'' (also known as PRA) is a monthly peer-reviewed scientific journal published by the American Physical Society covering atomic, molecular, and optical physics and quantum information. the editor was Jan M. Rost (Max Planck Institute for the Physics of Complex Systems). History In 1893, the ''Physical Review'' was established at Cornell University. It was taken over by the American Physical Society (formed in 1899) in 1913. In 1970, ''Physical Review'' was subdivided into ''Physical Review A'', ''B'', ''C'', and ''D''. At that time section ''A'' was subtitled ''Physical Review A: General Physics''. In 1990 a process was started to split this journal into two, resulting in the creation of '' Physical Review E'' in 1993. Hence, in 1993, ''Physical Review A'' changed its statement of scope to ''Atomic, Molecular and Optical Physics.'' In January 2007, the section of ''Physical Review E'' that published papers on classical optics was merged into ''Physical Revie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polytechnic University Of Milan
The Polytechnic University of Milan () is the largest technical university in Italy, with about 42,000 students. The university offers undergraduate, graduate and higher education courses in engineering, architecture and design. Founded in 1863, it is the oldest university in Milan. The Polytechnic University of Milan has two main campuses in the city of Milan, Italy, where the majority of the research and teaching activities are located, as well as other satellite campuses in five other cities across the Lombardy and Emilia-Romagna regions. The central offices and headquarters are located in the historical campus of Città Studi in Milan, which is also the largest, active since 1927. According to the QS World University Rankings for the subject area 'Engineering & Technology', it ranked in 2022 as the 13th best in the world. It ranked 6th worldwide for Design, 9th for Civil and Structural Engineering, 9th for Mechanical, Aerospace Engineering and 7th for Architecture. Its n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thin Film
A thin film is a layer of material ranging from fractions of a nanometer ( monolayer) to several micrometers in thickness. The controlled synthesis of materials as thin films (a process referred to as deposition) is a fundamental step in many applications. A familiar example is the household mirror, which typically has a thin metal coating on the back of a sheet of glass to form a reflective interface. The process of silvering was once commonly used to produce mirrors, while more recently the metal layer is deposited using techniques such as sputtering. Advances in thin film deposition techniques during the 20th century have enabled a wide range of technological breakthroughs in areas such as magnetic recording media, electronic semiconductor devices, integrated passive devices, LEDs, optical coatings (such as antireflective coatings), hard coatings on cutting tools, and for both energy generation (e.g. thin-film solar cells) and storage ( thin-film batteries). It is also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thin Film Coherent Perfect Absorber
Thin may refer to: * a lean body shape. ''(See also: emaciation, underweight)'' * ''Thin'' (film), a 2006 HBO documentary about eating disorders * Paper Thin (other), referring to multiple songs * Thin (web server), a Ruby web-server based on Mongrel *Thin (name) See also * * * Thin client, a computer in a client-server architecture network. * Thin film, a material layer of about 1 μm thickness. * Thin-film deposition, any technique for depositing a thin film of material onto a substrate or onto previously deposited layers * Thin film memory, high-speed variation of core memory developed by Sperry Rand in a government-funded research project * Thin-film optics, the branch of optics that deals with very thin structured layers of different materials * Thin layer chromatography (TLC), a chromatography technique used in chemistry to separate chemical compounds * Thin layers (oceanography), congregations of phytoplankton and zooplankton in the water column * Thin len ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon
Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic table: carbon is above it; and germanium, tin, lead, and flerovium are below it. It is relatively unreactive. Because of its high chemical affinity for oxygen, it was not until 1823 that Jöns Jakob Berzelius was first able to prepare it and characterize it in pure form. Its oxides form a family of anions known as silicates. Its melting and boiling points of 1414 °C and 3265 °C, respectively, are the second highest among all the metalloids and nonmetals, being surpassed only by boron. Silicon is the eighth most common element in the universe by mass, but very rarely occurs as the pure element in the Earth's crust. It is widely distributed in space in cosmic dusts, planetoids, and planets as various forms of silicon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photon
A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are Massless particle, massless, so they always move at the speed of light, speed of light in vacuum, (or about ). The photon belongs to the class of bosons. As with other elementary particles, photons are best explained by quantum mechanics and exhibit wave–particle duality, their behavior featuring properties of both waves and particles. The modern photon concept originated during the first two decades of the 20th century with the work of Albert Einstein, who built upon the research of Max Planck. While trying to explain how matter and electromagnetic radiation could be in thermal equilibrium with one another, Planck proposed that the energy stored within a material object should be regarded as composed of an integer number of discrete, equal-sized parts. To explai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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