NationMaster - Encyclopedia: Laser surgery

Soon after the invention of the laser in 1960, it was described as "a solution in search of a problem". However, since that time, the laser has found a place as a useful tool in many scientific, military, medical and industrial applications. Image:Laser effects. ... Image:Laser effects. ... Lasers range in size from microscopic diode lasers (top) with numerous applications, to football field sized neodymium glass lasers (bottom) used for inertial confinement fusion, nuclear weapons research and other physics experiments. ... 1960 (MCMLX) was a leap year starting on Friday (the link is to a full 1960 calendar). ... Lasers range in size from microscopic diode lasers (top) with numerous applications, to football field sized neodymium glass lasers (bottom) used for inertial confinement fusion, nuclear weapons research and other physics experiments. ...

Scientific

Spectroscopy

Most types of laser are an inherently pure source of light; they emit near-monochromatic light with a very well defined range of wavelengths. By careful design of the laser components, it is possible to improve the purity of the laser light (measured as the linewidth) beyond that of any other light source. This makes the laser a very useful source for spectroscopy. The high intensity of light that can be achieved in a small, well collimated beam can also be used to induce a nonlinear optical effect in a sample, which makes techniques such as Raman spectroscopy possible. Other spectroscopic techniques based on lasers can be used to make extremely sensitive detectors of various molecules, able to measure molecular concentrations in the parts-per-trillion (ppt) level. Due to the high power densities achievable by lasers, beam induced atomic emission is possible, this technique is termed Laser induced breakdown spectroscopy (LIBS). Lasers may also be indirectly used in spectroscopy as a micro-sampling system, a technique termed Laser ablation (LA), which is typically applied to ICP-MS apparatus resulting in the powerful LA-ICP-MS. Extremely high resolution spectrum of the Sun showing thousands of elemental absorption lines (fraunhofer lines) Spectroscopy is the study of spectra, that is, the dependence of physical quantities on frequency. ... Raman spectroscopy is a spectroscopic technique used in condensed matter physics and chemistry to study vibrational, rotational, and other low-frequency modes in a system. ... Schematic of a LIBS system - Courtesy of US Army Research Laboratory Laser Induced Breakdown Spectroscopy (LIBS) is a type of atomic emission spectroscopy which utilises a highly energetic laser pulse as the excitation source. ... Ablation is defined as the removal of material from the surface of an object by vaporization, chipping, or other erosive processes. ... ICP-MS (Inductively Coupled Plasma Mass Spectrometry) is a type of mass spectrometry that is highly sensitive and capable of analysis of a range of metals and several non-metals at below one part in 1012. ...

Lunar laser ranging

When the Apollo astronauts visited the moon, they planted retroreflector arrays to make possible the Lunar Laser Ranging Experiment. Laser beams are focused through large telescopes on Earth aimed toward the arrays, and the time taken for the beam to be reflected back to Earth measured to determine the distance between the Earth and Moon with high precision. A retroreflector is a device that sends light or other radiation back where it came from regardless of the angle of incidence, unlike a mirror, which does that only if the mirror is exactly perpendicular to the light beam. ... Categories: Physics stubs | Measuring instruments | Astronomy | General relativity | Apollo program ... 50 cm refracting telescope at Nice Observatory. ...

Photochemistry

Some laser systems, through the process of modelocking, can produce extremely brief pulses of light - as short as picoseconds or femtoseconds (10^-12 - 10^-15 seconds). Such pulses can be used to initiate and analyse chemical reactions, a technique known as photochemistry. The short pulses can be used to probe the process of the reaction at a very high temporal resolution, allowing the detection of short-lived intermediate molecules. This method is particularly useful in biochemistry, where it is used to analyse details of protein folding and function. Modelocking is a technique in optics by which a laser can be made to produce pulses of light of extremely short duration, on the order of picoseconds (10-12s) or femtoseconds (10-15s). ... Look up second in Wiktionary, the free dictionary. ... Biochemistry is the study of the chemistry of life, a bridge between biology and chemistry that studies how complex chemical reactions give rise to life. ...

Laser cooling

A technique that has had recent success is laser cooling. This involves ion trapping, a method where a number of ions are confined in a specially shaped arrangement of electric and magnetic fields. By shining particular wavelengths of laser light at the ions, it is possible to transfer momentum from the ions to the light photons, causing the ions to lose energy and to slow down, thus cooling the ions. If this process is continued, eventually all the ions in the trap are slowed and have the same energy level, forming an unusual arrangement of matter known as a Bose-Einstein condensate. In physics, an electric field or E-field is an effect produced by an electric charge (or a time-varying magnetic field) that exerts a force on charged objects in the field. ... It has been suggested that Magnetic field density be merged into this article or section. ... In physics, momentum is the product of the mass and velocity of an object. ... A Bose-Einstein condensate is a phase of matter formed by bosons cooled to temperatures very near to absolute zero. ...

Nuclear fusion

The most extravagant use of lasers in science is in the field of fusion research. Some of the world's most powerful and complex arrangements of multiple lasers and optical amplifiers are used to produce extremely high intensity pulses of light of extremely short duration. These pulses are arranged such that they impact pellets of tritium-deuterium simultaneously from all directions, hoping that the squeezing effect of the impacts will induce atomic fusion in the pellets. This technique, known as inertial confinement fusion so-far has not been able to achieve breakeven, that is, less power is generated by the fusion reaction than is used to power the lasers, but research continues. Tritium (symbol T or 3H) is a radioactive isotope of hydrogen. ... Deuterium, also called heavy hydrogen, is a stable isotope of hydrogen with a natural abundance of one atom in 6500 of hydrogen. ... The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing fusion power. ... Inertial confinement fusion using lasers rapidly progressed in the late 1970s and early 1980s from being able to deliver only a few joules of laser energy to a fusion target to being able to deliver tens of kilojoules to a target. ...

As a finderscope for amateur telescopes

With the advent of higher power green laser pointers came a new product line for observational astronomers -- the laser finder. Akin to the laser sighting device used in military rifles, a green laser mounted to the tube of a telescope and properly collimated can reveal the precise location in the sky that the telescope is pointed. In most outdoor night locales, the green beam of the laser is visible to the eye. By moving the telescope (and the laser beam) to the proper location in the sky, observers can more easily locate the intended celestial target.

Microscopy

Confocal laser scanning microscopy and Two-photon excitation microscopy make use of lasers to obtain blur-free images of thick specimens at various depths. Confocal laser scanning microscopy (CLSM or LSCM) is a valuable tool for obtaining high resolution images and 3-D reconstructions. ... Two-photon excitation microscopy is a technique that allows imaging living tissue up to a depth of one millimeter. ...

Military

Defensive applications

Recently, some progress has been made in the use of the laser as a directed energy weapon, mostly in defensive applications. By using a chemical laser, one in which the laser operation is powered by an energetic chemical reaction, the requirement for generating and storing a large amount of electrical energy (which directly or indirectly is used to power most high-power lasers) is removed. This makes the laser system much more compact, and easier to transport. One example is a laser system which is designed to destroy missiles in flight. It is mounted in a converted commercial airliner, and could be used, for example, to protect assets such as AWACS aircraft or to destroy ballistic missiles (see Airborne Laser). However, the practical problems of reliably generating and aiming the laser beam remain formidable. US Air Force E-3 Sentry AWACS aircraft is prepared for flight in November 1997 Cockpit of RAF E-3 Sentry undergoing upgrades Airborne Warning and Control System (AWACS) is a radar-based electronic system designed to carry out airborne surveillance, and C3 (command, control and communications) functions for both... The Airborne Laser (ABL) weapons system is designed to shoot down ballistic missiles in their boost stage. ...

The Mobile Tactical High-Energy Laser (MTHEL) is another defensive laser system under development; this is envisioned as a field-deployable weapon system able to track incoming artillery projectiles and cruise missiles by radar and destroy them with a powerful deuterium fluoride laser. The Tactical High-Energy Laser, or THEL, is a laser developed for military use. ... Historically, artillery refers to any engine used for the discharge of projectiles during war. ... A Tomahawk cruise missile A cruise missile is a guided missile which uses a lifting wing and most often a jet propulsion system to allow sustained flight. ... M*A*S*H , see Corporal Walter (Radar) OReilly. ... Hydrogen fluoride laser is an infrared chemical laser. ...

For a discussion and list of laser-based weapon systems, see also Directed-energy weapon#Lasers. A directed-energy weapon is a type of energy weapon that directs energy in a particular direction by a means other than a projectile. ...

Strategic Defense Initiative

Another example of direct use of a laser as a defensive weapon was researched for the Strategic Defense Initiative (SDI, nicknamed "Star Wars"), and its successor programs. This project would use ground-based or space-based laser systems to destroy incoming intercontinental ballistic missiles (ICBMs). Again, the practical problems of using and aiming these systems would be many; particularly the problem of destroying ICBMs at the most opportune moment, the boost phase just after launch. This would involve directing a laser through a large distance in the atmosphere, which, due to optical scattering and refraction, would bend and distort the laser beam, complicating the aiming of the laser and reducing its efficiency. The Strategic Defense Initiative (SDI), commonly called Star Wars after the popular science fiction series, was a system proposed by U.S. President Ronald Reagan on March 23, 1983 to use space-based systems to protect the United States from attack by strategic nuclear missiles. ... The cover of the 2004 DVD widescreen release of the modified original Star Wars Trilogy. ... A Minuteman III missile soars after a test launch. ... The straw seems to be broken, due to refraction of light as it emerges into the air. ...

Another idea to come from the SDI project was the nuclear-pumped X-ray laser. This was essentially an orbiting atomic bomb, surrounded by laser media in the form of glass rods; when the bomb exploded, the rods would be bombarded with highly-energetic gamma-ray photons, causing spontaneous and stimulated emission of X-ray photons in the atoms making up the rods. This would lead to optical amplification of the X-ray photons, producing an X-ray laser beam which would be minimally affected by atmospheric distortion and capable of destroying ICBMs in flight. The X-ray laser would be a strictly one-shot device, destroying itself on activation. Some initial tests of this concept were performed with underground nuclear testing, however, the results were not encouraging. Research into this approach to missile defense was discontinued after the cancellation of the SDI program. The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 km (11 mi) above the epicenter. ... This article is about electromagnetic radiation. ... In physics, the photon (from Greek Ï†Ï‰Ï‚, phÅs, meaning light) is the quantum of the electromagnetic field; for instance, light. ... 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. ... In optics, styimulated emission is the process by which, when perturbed by a photon, matter may lose energy resulting in the creation of another photon. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz...

In recent years, the United States Air Force has begun experimenting with using lasers combined with high-altitude airships as a potential means for a missile defense shield but also as a means to destroy enemy spacecraft or satellites in low-earth orbit. For more information, see Evolutionary Air and Space Global Laser Engagement. The United States Air Force (USAF) is the aerospace branch of the United States armed forces. ... USS Akron (ZRS-4) in flight, 2 November 1931 An airship is a buoyant aircraft that can be steered and propelled through the air. ... A satellite is any object that orbits another object (which is known as its primary). ... In physics, an orbit is the path that an object makes, around another object, whilst under the influence of a source of centripetal force, such as gravity. ... The Evolutionary Air and Space Global Laser Engagement, or EAGLE for short, is a new plan being developed by the United States Air Forces Missile Defense Agency. ...

Laser sight

The laser has in most military applications been used as a tool to enhance the targeting of other weapon systems. For example, a laser sight is a small, usually visible-light laser placed on a handgun or rifle aligned to emit a beam parallel to the barrel. Since a laser beam typically has low divergence, the laser light appears as a small spot even at long distances; the user simply places the spot on the desired target and the barrel of the gun is aligned. Recent studies (2001) have shown that laser sight has become an effective deterring tool for law enforcement. Criminals are more likely to surrender without resistance when they find a red laser dot on their chest.

Most laser sights utilize a red (670–633 nm) diode, with the 633–635 nm diodes being an estimated 10 times as bright as their 670 nm counterparts. Some laser sights used an infrared diode, which produced a dot invisible to the naked human eye, but would show up when special optics were employed by the user. In the late 90's, green diodes (532 nm) became available.

Modern laser sights are so small that they can fit below the barrel as part of gun instead of a separate attachment. Some laser sights, such as ones produced by LaserMax, are actually integrated into a unit that replaces the entire guide rod of a pistol, thus adding no bulk to the weapon. Others, like Crimson Trace Lasergrips, are built into the grip so that activation is automatic as soon as the weapon is used.

Another type of laser sight is the reflex, or red dot sight. This gives the illusion of a red dot being projected onto the target once the shooter looks through the sight, but it is only visible to the user. This has advantages where multiple weapons are aimed at the same target, and it is also more visible than a conventional laser in bright sunny conditions. The red dot sight or reflex sight is an optical firearm sight (also used as an aiming sight for telescopes) that uses a refractive or reflective lens to generate a collimated image of a luminous or reflective reticle. ...

Illuminator

This menacing but allegedly "non-lethal" laser weapon, shown in the accompanying photo attached to an M16 rifle, was developed by the U.S. Air Force to temporarily impair an adversary’s ability to fire a weapon or to otherwise threaten enemy forces. The Saber 203 briefly illuminates an opponent with harmless, low-power laser light. Realizing he has been targeted, the aggressor (according to the Air Force) hides or flees rather than risk death by aiming his weapon and attracting defensive fire. Non-lethal laser weapon (U.S. Air Force) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Non-lethal laser weapon (U.S. Air Force) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... M16 is the U.S. Military designation for a family of rifles derived from the ArmaLite AR-15. ...

Rangefinder

Main article: Laser range-finder It has been suggested that this article or section be merged with LIDAR. (Discuss) A laser range-finder, or LIDAR (LIght Detection And Ranging), is a device which uses a laser beam in order to determine the distance to an opaque object. ...

A laser range-finder is a device consisting of a pulsed laser and a light detector. By measuring the time taken for light to reflect off a far object, and knowing the speed of light, the range to the object can be found. A laser rangefinder is thus a simple form of LIDAR. The distance to the target can then be used to aim a weapon such as a tank's main gun. LIDAR (Light Detection and Ranging; or Laser Imaging Detection and Ranging) is a technology that determines distance to an object or surface using laser pulses. ...

Target designator

Another military use of lasers is as a laser target designator. This is a low-power laser pointer used to indicate a target for a precision-guided munition, typically launched from an aircraft. The guided munition adjusts its flight-path to home in to the laser light reflected by the target, enabling a great precision in aiming. The laser designator can be shone onto the target by an aircraft or nearby infantry. Lasers used for this purpose are usually infrared lasers, to prevent easy detection of the guiding laser light by the enemy. A keychain laser pointer. ... BOLT-117 laser guided bomb Precision-guided munitions (smart munitions or smart bombs) are self-guiding weapons intended to maximize damage to the target while minimizing collateral damage. Because the damage effects of an explosive weapon scale as a power law with distance, quite modest improvements in accuracy (and hence... Image of a small dog taken in mid-infrared (thermal) light (false color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of microwave radiation. ...

Death ray

The first role envisioned for the laser in military applications was as a "death ray": a hand-held device that might replace the gun as a weapon for infantry, or a vehicle-mounted "laser cannon" able to destroy tanks, ships and aircraft. However, practical considerations have severely constrained these ideas; any laser capable of seriously wounding a human would (with its requisite power supply) be inevitably too heavy for a single soldier to lift, and a high-power laser capable of burning through tank armour would be extremely complex and very sensitive to misalignment from any knocks or vibration it might suffer, making it unsuitable for field deployment. 155 mm M198 howitzer U.S. Army soldier with a compact M249 variant USS Iowa (BB-61) fires a full broadside of nine 16/50 and six 5/38 guns during a target exercise near Vieques Island, Puerto Rico, 1 July 1984. ... The bayonet, still used in war as both knife and spearpoint. ... Infantry of the Royal Irish Rifles during the Battle of the Somme, First World War. ...

There remains the possibility of using lasers to blind, since this requires much lower power levels, and is easily achievable in a man portable unit. However, most nations regard the deliberate blinding of the enemy as forbidden by the rules of war. Russia, China, and Jordan possess such weapons, which were banned in most western countries in 1980. The two parts of the laws of war: Law concerning acceptable practices while engaged in war, like the Geneva Conventions, is called Jus in bello; while law concerning allowable justifications for armed force is called Jus ad bellum. ...

Medical

Epilation performed by laser was performed experimentally for about 20 years before it became commercially available in the mid 1990s. ... LASIK, an acronym for Laser-assisted In Situ Keratomileusis, is a form of refractive laser eye surgery procedure performed by ophthalmologists intended for correcting vision. ... This article or section should be merged with Photorefractive keratectomy LASEK, an acronym for Laser-Assisted Sub-Epithelial Keratectomy, is an eye surgery procedure intended to reduce a persons dependency on glasses or contact lenses. ... Photorefractive keratectomy (PRK) and Laser-Assisted Sub-Epithelial Keratectomy (LASEK) are laser eye surgery procedures intended to correct a persons vision and reduce their dependency on glasses or contact lenses. ... A laser scalpel is a scalpel for surgery, cutting tissue by the energy of laser light. ... Photobiomodulation also called Low Level Laser Therapy (LLLT), Cold Laser Therapy, Laser Biostimulation, phototherapy or just Laser Therapy. ...

Industrial & commercial

Category: Lasers Laser cutting is a technology which uses a laser to cut materials, and is usually used in industrial manufacturing. ... Welding is a fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence. ... A rangefinder is an optical device that allows distance to be estimated or measured using triangulation, laser, radar, or other method. ... Surveillance is the monitoring of behavior. ... LIDAR (Light Detection and Ranging; or Laser Imaging Detection and Ranging) is a technology that determines distance to an object or surface using laser pulses. ... A compact disc player or CD player is an electronic device to play audio from compact discs. ... This page relates to a hardware device used to play DVDs. ... Laser printer A laser printer is a common type of computer printer that produces high quality printing, and is able to produce both text and graphics. ... A digital minilab is a computer printer that uses traditional chemical photographic processes to make prints of digital images. ... A typical barcode scanner. ... This article may be too technical for most readers to understand. ... A keychain laser pointer. ... Holography (from the Greek, ÎŒÎ»Î¿Ï‚-holos whole + Î³ÏÎ±Ï†Î®-graphe writing) is the science of producing holograms, an advanced form of photography that allows an image to be recorded in three dimensions. ... Laser show as seen during the Chaos Communication Camp in 2003 A laser lighting display or laser light show involves the use of laser light to entertain an audience. ... Photolithography is a process used in semiconductor device fabrication to transfer a pattern from a photomask (also called reticle) to the surface of a substrate. ... Optical communication is any form of telecommunication that uses light as the transmission medium. ... Optical fibers An optical fiber (or fibre) is a transparent thin fiber, usually made of glass or plastic, for transmitting light. ... Free-space optical communication involves the use of optical links across the space between two points, either within the Earths atmosphere, or in outer space. ... A guidance system is a device or group of devices used to navigate a ship, aircraft, missile, rocket, satellite, or other craft. ... Note: This page does not refer to a fiber optic gyroscope, even though the user is directed here when seaching for that term. ... Optical tweezers make use of a laser beam to provide a mechanical force (in the range of pico to femto Newtons) to physically move microscopic objects (nanometers to tens of micrometer) around with nanometer precision. ... In printed material In printed material, a subtitle is an explanatory or alternate title. ... For other uses see film (disambiguation) Film refers to the celluliod media on which movies are printed Film — also called movies, the cinema, the silver screen, moving pictures, photoplays, picture shows, flicks, or motion pictures, — is a field that encompasses motion pictures as an art form or as part of... This article is about motion pictures. ... A space elevator would consist of a cable attached to the surface and reaching outwards into space. ... Climbers on Valkyrie at the Roaches. ... Lasers range in size from microscopic diode lasers (top) with numerous applications, to football field sized neodymium glass lasers (bottom) used for inertial confinement fusion, nuclear weapons research and other physics experiments. ... Microwave image of 3C353 galaxy at 8. ... Moving energy from one place to another through empty space (or air) is called beaming. Beaming enough energy to run a machine (such as a vehicle) is called power beaming. ... Various meters In classical physics and engineering, measurement generally refers to the process of estimating or determining the ratio of a magnitude of a quantitative property or relation to a unit of the same type of quantitative property or relation. ... Laser Scanning - also known as Digitizing or 3D Digitizing- is a process that uses light to capture the shape of three-dimensional objects and re-create them in a virtual workspace. ...

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