An excimer laser is a form of ultraviolet chemical laser which is commonly used in eye surgery and semiconductor manufacturing. The solar corona as seen in deep ultraviolet light at 17. ... A chemical laser is a laser that obtains its energy from a chemical reaction. ... Eye surgery in the middle ages. ... A semiconductor is a solid whose electrical conductivity can be controlled over a wide range, either permanently or dynamically. ...

An excimer laser typically uses a combination of an inert gas (Argon, krypton, or xenon) and a reactive gas (fluorine or chlorine). Under the appropriate conditions of electrical stimulation, a pseudo-molecule called a dimer is created, which can only exist in an energised state and can give rise to laser light in the ultraviolet range. This light is exceptionally well focussed and capable of very delicate control, and is well absorbed by biological matter and organic compounds. These properties make excimer lasers well suited to precision micromachining organic material (including certain polymers and plastics), or delicate surgeries such as eye surgery (LASIK). Kansas State University pioneered the study of the excimer laser which made LASIK surgery possible.^{[citation needed]} A laser system generally consists of three important parts: An energy source (usually referred to as the pump or pump source); A gain medium or laser medium; A mirror, or system of mirrors, forming an optical resonator. ... In English, to be inert is to be in a state of doing little or nothing. ... General Name, Symbol, Number argon, Ar, 18 Chemical series noble gases Group, Period, Block 18, 3, p Appearance colorless Atomic mass 39. ... General Name, Symbol, Number krypton, Kr, 36 Chemical series noble gases Group, Period, Block 18, 4, p Appearance colorless Atomic mass 83. ... General Name, Symbol, Number xenon, Xe, 54 Chemical series noble gases Group, Period, Block 18, 5, p Appearance colorless Atomic mass 131. ... This article is about electronics. ... General Name, Symbol, Number fluorine, F, 9 Chemical series halogens Group, Period, Block 17, 2, p Appearance Yellowish brown gas Atomic mass 18. ... General Name, Symbol, Number chlorine, Cl, 17 Chemical series halogens Group, Period, Block 17, 3, p Appearance yellowish green Atomic mass 35. ... In chemistry, a molecule is an aggregate of two or more atoms in a definite arrangement held together by chemical bonds [1] [2] [3] [4] [5]. Chemical substances are not infinitely divisible into smaller fractions of the same substance: a molecule is generally considered the smallest particle of a pure... Sucrose, or common table sugar, is composed of glucose and fructose. ... A LASER (from the acronym of Light Amplification by Stimulated Emission of Radiation) is an optical source that emits photons in a coherent beam. ... The solar corona as seen in deep ultraviolet light at 17. ... Biological matter or biological material refers to the unique, highly organized substances of which cellular life is composed of, for instance membranes, proteins, and nucleic acids. ... Benzene is the simplest of the arenes, a family of organic compounds An organic compound is any member of a large class of chemical compounds whose molecules contain carbon and hydrogen; therefore, carbides, carbonates, carbon oxides and elementary carbon are not organic (see below for more on the definition controversy... Polymer is a term used to describe large molecules consisting of repeating structural units, or monomers, connected by covalent chemical bonds. ... A cardiothoracic surgeon performs a mitral valve replacement at the Fitzsimons Army Medical Center. ... The human eye. ... LASIK, an acronym for Laser-Assisted in Situ Keratomileusis, is a form of refractive laser eye surgery procedure performed by ophthalmologists intended for correcting myopia, hyperopia, and astigmatism. ... Kansas State University (sometimes referred to as K-State) is an institution of higher learning located in Manhattan, Kansas, in the United States. ...

Rather than burning or cutting material, the excimer laser adds enough energy to disrupt the molecular bonds of the surface tissue, which effectively disintegrates into the air in a tightly controlled manner through ablation rather than burning. Thus excimer lasers have the useful property that they can remove exceptionally fine layers of surface material with almost no heating or change to the remainder of the material which is left intact. Look up disintegration, disintegrate in Wiktionary, the free dictionary. ... Ablation is defined as the removal of material from the surface of an object by vaporization, chipping, or other erosive processes. ...

The term excimer is short for 'excited dimer'. Excimer energy diagram An excimer (originally short for excited dimer) is a short-lived dimeric or heterodimeric molecule formed from two species, at least one of which is in an electronic excited state. ... Sucrose, or common table sugar, is composed of glucose and fructose. ...

Excimer lasers

The first excimer laser was invented in 1971 by Nikolai Basov, V. A. Danilychev and Yu. M. Popov, at the P. N. Lebedev Physical Institute in Moscow, using a xenon dimer (Xe₂) excited by an electron beam to give stimulated emission at 172 nm wavelength. A later improvement was the use of noble gas halides (originally XeBr), invented (and patented) in 1975 by George Hart and Stuart Searles of the United States Government's Naval Research Laboratory. 1971 (MCMLXXI) was a common year starting on Friday (the link is to a full 1971 calendar). ... Nikolay Gennadiyevich Basov (Russian:Николай Геннадиевич Басов) (December 14, 1922 – July 1, 2001) was a Soviet/Russian physicist and educator. ... Location Position of Moscow in Europe Government Country District Subdivision Russia Central Federal District Federal City Mayor Yuriy Luzhkov Geographical characteristics Area  - City 1,081 km² Population  - City (2005)    - Density 10,415,400   8537. ... General Name, Symbol, Number xenon, Xe, 54 Chemical series noble gases Group, Period, Block 18, 5, p Appearance colorless Atomic mass 131. ... Sucrose, or common table sugar, is composed of glucose and fructose. ... The electron is a fundamental subatomic particle that carries an electric charge. ... In optics, stimulated emission is the process by which, when perturbed by a photon, matter may lose energy resulting in the creation of another photon. ... A metre (American spelling: meter; symbol: m) is a unit of length and the current base unit of length in the International System of Units (SI). ... For the musical band, see Noble Gas (band) The noble gases are the chemical elements in group 18 (old-style Group 0) of the periodic table. ... The halogens are a chemical series. ... General Name, Symbol, Number xenon, Xe, 54 Chemical series noble gases Group, Period, Block 18, 5, p Appearance colorless Atomic mass 131. ... General Name, Symbol, Number bromine, Br, 35 Chemical series halogens Group, Period, Block 17, 4, p Appearance gas/liquid: red-brown solid: metallic luster Atomic mass 79. ... 1975 (MCMLXXV) was a common year starting on Wednesday. ... George A. Hart is a physicist best known for the invention of the excimer laser. ... -1...

In 1980 - 1983, Dr. Samuel Blum was working with Dr. Rangaswamy Srinivasan and James Wynne at IBM’s T. J. Watson Research Center when they observed the effect of the ultraviolet excimer laser on biological materials. Intrigued, they investigated further, finding that the laser made clean, precise cuts that would be ideal for delicate surgeries. For their work, they were awarded patent #4,784,135 and Dr. Blum and Dr. Rangaswamy Srinivasan were elected to the National Inventors Hall of Fame in 2002[1]. James Wynne (born in Newcastle, New South Wales) was an Australian rugby league player for the Newcastle Knights in the National Rugby League competition. ... Big Blue redirects here. ... The Thomas J. Watson Research Center is the headquarters for the IBM Research Division. ... The National Inventors Hall of Fame is an organization that honors important inventors from the United States. ...

Laser action in an excimer molecule occurs because it has a bound (associative) excited state, but a repulsive (disassociative) ground state. This is because noble gases such as xenon and krypton are highly inert and do not usually form chemical compounds. However, when in an excited state (induced by an electrical discharge or high-energy electron beams, which produce high energy pulses), they can form temporarily-bound molecules with themselves (dimers) or with halides (complexes) such as fluorine and chlorine. The excited compound can give up its excess energy by undergoing spontaneous or stimulated emission, resulting in a strongly-repulsive ground state molecule which very quickly (on the order of a picosecond) disassociates back into two unbound atoms. This forms a population inversion between the two states. It has been suggested that this article or section be merged with quantum state. ... In physics, the ground state of a quantum mechanical system is its lowest-energy state. ... General Name, Symbol, Number krypton, Kr, 36 Chemical series noble gases Group, Period, Block 18, 4, p Appearance colorless Atomic mass 83. ... In English, to be inert is to be in a state of doing little or nothing. ... A chemical compound is a chemical substance consisting of two or more different chemically bonded chemical elements, with a fixed ratio determining the composition. ... Synthesis of copper(II)-tetraphenylporphine, a metal complex, from tetraphenylporphine and copper(II) acetate monohydrate. ... General Name, Symbol, Number fluorine, F, 9 Chemical series halogens Group, Period, Block 17, 2, p Appearance Yellowish brown gas Atomic mass 18. ... General Name, Symbol, Number chlorine, Cl, 17 Chemical series halogens Group, Period, Block 17, 3, p Appearance yellowish green Atomic mass 35. ... Spontaneous emission is the process by which a molecule in an excited state drops to the ground state, resulting in the creation of a photon. ... A picosecond is an SI unit of time equal to 10-12 of a second. ... In physics, specifically statistical mechanics, the concept of population inversion is of fundamental importance in laser science because the production of a population inversion is a necessary step in the workings of a laser. ...

Most "excimer" lasers are of the noble gas halide type, for which the term excimer is strictly speaking a misnomer (since a dimer refers to a molecule of two identical or similar parts): The correct but less commonly used name for such is exciplex laser.

The wavelength of an excimer laser depends on the molecules used, and is usually in the ultraviolet: The wavelength is the distance between repeating units of a wave pattern. ...

Excimer lasers are usually operated with a pulse rate of around 100 Hz and a pulse duration of ~10 ns, although some operate as high as 8 kHz and 30 ns. Their high-power ultraviolet output makes them useful for surgery (particularly eye surgery), for lithography for semiconductor manufacturing, and for dermatological treatment. They are quite large and bulky devices, which is a disadvantage in their medical applications, although their size is rapidly decreasing with ongoing development. The hertz (symbol: Hz) is the SI unit of frequency. ... To help compare orders of magnitude of different times this page lists times between 10−9 seconds and 10−8 seconds (1 nanosecond and 10 nanoseconds) See also times of other orders of magnitude. ... Negative lithography stone and positive print of a map of Munich. ...

For electric discharge pump see: Nitrogen laser. This article needs to be cleaned up to conform to a higher standard of quality. ...

Uses

Excimer laser light is typically absorbed within the first billionth of a meter (nanometer) of tissue. The website howstuffworks.com states: A nanometre (American spelling: nanometer) is 1. ...

"The Excimer laser is incredibly precise. It has the ability to focus a beam as small as 0.25 micrometres [and] capable of removing 0.5% of a human hair's width at a time."

This quote is a bit misleading. The beam output from on excimer is in general multimode and not of good quality when compared to other lasers. In laser drilling systems the excimer is employed similar to a conventional light source. The accuracy comes from the imaging system and the fact that UV light has a short wavelength.

See also

• Krypton fluoride laser
• Excimer