List of laser applications

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Laser pointers in different colours Lasers.jpeg
Laser pointers in different colours

Many scientific, military, medical and commercial laser applications have been developed since the invention of the laser in 1958. The coherency, high monochromaticity, and ability to reach extremely high powers are all properties which allow for these specialized applications.

Contents

Scientific

In science, lasers are used in many ways, including:

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.

The principles of laser spectroscopy are discussed by Demtröder. [3]

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, the purity of the laser light (measured as the "linewidth") can be improved more than the purity 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-1012 (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).

Heat treatment

Heat treating with the lasers allows selective surface hardening against wear with little or no distortion of the component. Because this eliminates much part reworking that is currently done, the laser system's capital cost is recovered in a short time. An inert, absorbent coating for laser heat treatment has also been developed that eliminates the fumes generated by conventional paint coatings during the heat-treating process with CO2 laser beams.

One consideration crucial to the success of a heat treatment operation is control of the laser beam irradiance on the part surface. The optimal irradiance distribution is driven by the thermodynamics of the laser-material interaction and by the part geometry.

Typically, irradiances between 500 and 5000 W/cm^2 satisfy the thermodynamic constraints and allow the rapid surface heating and minimal total heat input required. For general heat treatment, a uniform square or rectangular beam is one of the best options. For some special applications or applications where the heat treatment is done on an edge or corner of the part, it may be better to have the irradiance decrease near the edge to prevent melting.

Weather

Research shows that scientists may one day be able to induce rain and lightning storms (as well as micro-manipulating some other weather phenomena) using high energy lasers. Such a breakthrough could potentially eradicate droughts, help alleviate weather related catastrophes, and allocate weather resources to areas in need. [4] [5]

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 accuracy.

Photochemistry

Some laser systems, through the process of mode locking, 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 analyze 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.

Laser scanner

Laser barcode scanners are ideal for applications that require high speed reading of linear codes or stacked symbols.

Laser cooling

A technique that has recent success is laser cooling. This involves atom trapping, a method where a number of atoms are confined in a specially shaped arrangement of electric and magnetic fields. Shining particular wavelengths of light at the ions or atoms slows them down, thus cooling them. As this process is continued, they all are slowed and have the same energy level, forming an unusual arrangement of matter known as a Bose–Einstein condensate.

Nuclear fusion

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, e.g. laboratory for laser energetics, National Ignition Facility, GEKKO XII, Nike laser, Laser Mégajoule, HiPER. 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, so far the fusion reaction generates less power than is used to power the lasers, however; experiments at the National Ignition Facility were able to demonstrate fusion reactions that generate more energy than was contained within the lasers driving the reaction. [6]

Particle acceleration

Powerful lasers producing ultra-short (in the tens of femtoseconds) and ultra-intense (up to 1023 W/cm2) laser pulses offer much greater acceleration gradients than that of conventional accelerators. This fact is exploited in several plasma acceleration techniques used for accelerating both electrons and charged ions to high energies.

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. Laser capture microdissection use lasers to procure specific cell populations from a tissue section under microscopic visualization.

Additional laser microscopy techniques include harmonic microscopy, four-wave mixing microscopy [7] and interferometric microscopy. [8]

Military

Directly as an energy weapon

A laser weapon is directed-energy weapon based on lasers.

Defensive countermeasures

Defensive countermeasure applications can range from compact, low power infrared countermeasures to high power, airborne laser systems. IR countermeasure systems use lasers to confuse the seeker heads on infrared homing missiles.

Disorientation

Some weapons simply use a laser to disorient a person. One such weapon is the Thales Green Laser Optical Warner. [9]

Guidance

Laser guidance is a technique of guiding a missile or other projectile or vehicle to a target by means of a laser beam.

Target designator

A target designator DHY 307 laser target designator P1220816.jpg
A 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 beam of the laser target designator is set to a pulse rate that matches that set on the guided munition to ensure munitions strike their designated targets and do not follow other laser beams which may be in use in the area. The laser designator can be shone onto the target by an aircraft or nearby infantry. Lasers used for this purpose are usually infrared lasers, so the enemy cannot easily detect the guiding laser light.

Firearms

Laser sight

Laser sight used by the Israel Defense Forces during commando training Flickr - Israel Defense Forces - Nachal Brigade Reconnaissance Battalion in "Commando" Training (2).jpg
Laser sight used by the Israel Defense Forces during commando training
Smith & Wesson revolver equipped with a laser sight mounted on the trigger guard. S&W .357 Magnum With Laser Sight.jpg
Smith & Wesson revolver equipped with a laser sight mounted on the trigger guard.

The laser has in most firearms 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 a rifle and aligned to emit a beam parallel to the barrel. Since a laser beam has low divergence, the laser light appears as a small spot even at long distances; the user places the spot on the desired target and the barrel of the gun is aligned (but not necessarily allowing for bullet drop, windage, distance between the direction of the beam and the axis of the barrel, and the target mobility while the bullet travels).

Most laser sights use a red laser diode. Others use an infrared diode to produce a dot invisible to the naked human eye but detectable with night vision devices. The firearms adaptive target acquisition module LLM01 laser light module combines visible and infrared laser diodes. In the late 1990s, green diode pumped solid state laser (DPSS) laser sights (532 nm) became available.

Eye-targeted lasers

A non-lethal laser weapon 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. This unit illuminates an opponent with harmless low-power laser light and can have the effect of dazzling or disorienting the subject or causing them to flee. Several types of dazzlers are now available, and some have been used in combat.

There remains the possibility of using lasers to blind, since this requires relatively low power levels and is easily achievable in a man-portable unit. However, most nations regard the deliberate permanent blinding of the enemy as forbidden by the rules of war (see Protocol on Blinding Laser Weapons). Although several nations have developed blinding laser weapons, such as China's ZM-87, none of these are believed to have made it past the prototype stage.

In addition to the applications that cross over with military applications, a widely known law enforcement use of lasers is for lidar to measure the speed of vehicles.

Holographic weapon sight

A holographic weapon sight uses a laser diode to illuminate a hologram of a reticle built into a flat glass optical window of the sight. The user looks through the optical window and sees a cross hair reticle image superimposed at a distance on the field of view. [10]

Medical

Industrial and commercial

Lasers used for visual effects during a musical performance. (A laser light show.) Classical spectacular laser effects.jpg
Lasers used for visual effects during a musical performance. (A laser light show.)
Levelling of ceramic tiles floor with a laser device LaserFlooring1.jpg
Levelling of ceramic tiles floor with a laser device

Industrial laser applications can be divided into two categories depending on the power of the laser: material processing and micro-material processing.

In material processing, lasers with average optical power above 1 kilowatt are used mainly for industrial materials processing applications. Beyond this power threshold there are thermal issues related to the optics that separate these lasers from their lower-power counterparts. [11] Laser systems in the 50-300W range are used primarily for pumping, plastic welding and soldering applications. Lasers above 300W are used in brazing, thin metal welding, and sheet metal cutting applications. The required brightness (as measured in by the beam parameter product) is higher for cutting applications than for brazing and thin metal welding. [12] High power applications, such as hardening, cladding, and deep penetrating welding, require multiple kW of optical power, and are used in a broad range of industrial processes.

Micro material processing is a category that includes all laser material processing applications under 1 kilowatt. [13] The use of lasers in Micro Materials Processing has found broad application in the development and manufacturing of screens for smartphones, tablet computers, and LED TVs. [14]

A detailed list of industrial and commercial laser applications includes:

Entertainment and recreation

Surveying and ranging

Images

See also

Related Research Articles

<span class="mw-page-title-main">Laser</span> Device which emits light via optical amplification

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 anacronym that originated as an acronym for light amplification by stimulated emission of radiation. The first laser was built in 1960 by Theodore Maiman at Hughes Research Laboratories, based on theoretical work by Charles H. Townes and Arthur Leonard Schawlow.

<span class="mw-page-title-main">Microscopy</span> Viewing of objects which are too small to be seen with the naked eye

Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye. There are three well-known branches of microscopy: optical, electron, and scanning probe microscopy, along with the emerging field of X-ray microscopy.

<span class="mw-page-title-main">Laser diode</span> Semiconductor laser

A laser diode is a semiconductor device similar to a light-emitting diode in which a diode pumped directly with electrical current can create lasing conditions at the diode's junction.

<span class="mw-page-title-main">Dye laser</span> Equipment using an organic dye to emit coherent light

A dye laser is a laser that uses an organic dye as the lasing medium, usually as a liquid solution. Compared to gases and most solid state lasing media, a dye can usually be used for a much wider range of wavelengths, often spanning 50 to 100 nanometers or more. The wide bandwidth makes them particularly suitable for tunable lasers and pulsed lasers. The dye rhodamine 6G, for example, can be tuned from 635 nm (orangish-red) to 560 nm (greenish-yellow), and produce pulses as short as 16 femtoseconds. Moreover, the dye can be replaced by another type in order to generate an even broader range of wavelengths with the same laser, from the near-infrared to the near-ultraviolet, although this usually requires replacing other optical components in the laser as well, such as dielectric mirrors or pump lasers.

The term biophotonics denotes a combination of biology and photonics, with photonics being the science and technology of generation, manipulation, and detection of photons, quantum units of light. Photonics is related to electronics and photons. Photons play a central role in information technologies, such as fiber optics, the way electrons do in electronics.

<span class="mw-page-title-main">Nd:YAG laser</span> Crystal used as a lasing medium for solid-state lasers

Nd:YAG (neodymium-doped yttrium aluminum garnet; Nd:Y3Al5O12) is a crystal that is used as a lasing medium for solid-state lasers. The dopant, neodymium in the +3 oxidation state, Nd(III), typically replaces a small fraction (1%) of the yttrium ions in the host crystal structure of the yttrium aluminum garnet (YAG), since the two ions are of similar size. It is the neodymium ion which provides the lasing activity in the crystal, in the same fashion as red chromium ion in ruby lasers.

<span class="mw-page-title-main">Titanium-sapphire laser</span> Type of laser

Titanium-sapphire lasers (also known as Ti:sapphire lasers, Ti:Al2O3 lasers or Ti:sapphs) are tunable lasers which emit red and near-infrared light in the range from 650 to 1100 nanometers. These lasers are mainly used in scientific research because of their tunability and their ability to generate ultrashort pulses thanks to its broad light emission spectrum. Lasers based on Ti:sapphire were first constructed and invented in June 1982 by Peter Moulton at the MIT Lincoln Laboratory.

A diode-pumped solid-state laser (DPSSL) is a solid-state laser made by pumping a solid gain medium, for example, a ruby or a neodymium-doped YAG crystal, with a laser diode.

<span class="mw-page-title-main">Transparent ceramics</span> Ceramic materials that are optically transparent

Many ceramic materials, both glassy and crystalline, have found use as optically transparent materials in various forms from bulk solid-state components to high surface area forms such as thin films, coatings, and fibers. Such devices have found widespread use for various applications in the electro-optical field including: optical fibers for guided lightwave transmission, optical switches, laser amplifiers and lenses, hosts for solid-state lasers and optical window materials for gas lasers, and infrared (IR) heat seeking devices for missile guidance systems and IR night vision. In commercial and general knowledge domains, it is commonly accepted that transparent ceramics or ceramic glass are varieties of strengthened glass, such as those used for the screen glass on an iPhone.

<span class="mw-page-title-main">Laser safety</span> Protocols for safe use, design and implementation of laser technology

Laser radiation safety is the safe design, use and implementation of lasers to minimize the risk of laser accidents, especially those involving eye injuries. Since even relatively small amounts of laser light can lead to permanent eye injuries, the sale and usage of lasers is typically subject to government regulations.

<span class="mw-page-title-main">Tunable laser</span>

A tunable laser is a laser whose wavelength of operation can be altered in a controlled manner. While all laser gain media allow small shifts in output wavelength, only a few types of lasers allow continuous tuning over a significant wavelength range.

A vertical-external-cavity surface-emitting-laser (VECSEL) is a small semiconductor laser similar to a vertical-cavity surface-emitting laser (VCSEL). VECSELs are used primarily as near infrared devices in laser cooling and spectroscopy, but have also been explored for applications such as telecommunications.

<span class="mw-page-title-main">Yttrium aluminium garnet</span> Synthetic crystalline material of the garnet group

Yttrium aluminium garnet (YAG, Y3Al5O12) is a synthetic crystalline material of the garnet group. It is a cubic yttrium aluminium oxide phase, with other examples being YAlO3 (YAP) in a hexagonal or an orthorhombic, perovskite-like form, and the monoclinic Y4Al2O9 (YAM).

Ultrafast laser spectroscopy is a category of spectroscopic techniques using ultrashort pulse lasers for the study of dynamics on extremely short time scales. Different methods are used to examine the dynamics of charge carriers, atoms, and molecules. Many different procedures have been developed spanning different time scales and photon energy ranges; some common methods are listed below.

<span class="mw-page-title-main">Raman microscope</span> Laser microscope used for Raman spectroscopy

The Raman microscope is a laser-based microscopic device used to perform Raman spectroscopy. The term MOLE is used to refer to the Raman-based microprobe. The technique used is named after C. V. Raman, who discovered the scattering properties in liquids.

The technique of vibrational analysis with scanning probe microscopy allows probing vibrational properties of materials at the submicrometer scale, and even of individual molecules. This is accomplished by integrating scanning probe microscopy (SPM) and vibrational spectroscopy. This combination allows for much higher spatial resolution than can be achieved with conventional Raman/FTIR instrumentation. The technique is also nondestructive, requires non-extensive sample preparation, and provides more contrast such as intensity contrast, polarization contrast and wavelength contrast, as well as providing specific chemical information and topography images simultaneously.

<span class="mw-page-title-main">Infrared Nanospectroscopy (AFM-IR)</span> Infrared microscopy technique

AFM-IR or infrared nanospectroscopy is one of a family of techniques that are derived from a combination of two parent instrumental techniques. AFM-IR combines the chemical analysis power of infrared spectroscopy and the high-spatial resolution of scanning probe microscopy (SPM). The term was first used to denote a method that combined a tuneable free electron laser with an atomic force microscope equipped with a sharp probe that measured the local absorption of infrared light by a sample with nanoscale spatial resolution.

The Beckman Laser Institute is an interdisciplinary research center for the development of optical technologies and their use in biology and medicine. Located on the campus of the University of California, Irvine in Irvine, California, an independent nonprofit corporation was created in 1982, under the leadership of Michael W. Berns, and the actual facility opened on June 4, 1986. It is one of a number of institutions focused on translational research, connecting research and medical applications. Researchers at the institute have developed laser techniques for the manipulation of structures within a living cell, and applied them medically in treatment of skin conditions, stroke, and cancer, among others.

<span class="mw-page-title-main">Lightwave Electronics Corporation</span>

Lightwave Electronics Corporation was a developer and manufacturer of diode-pumped solid-state lasers, and was a significant contributor to the creation and maturation of this technology. Lightwave Electronics was a technology-focused company, with diverse markets, including science and micromachining. Inventors employed by Lightwave Electronics received 51 US patents, and Lightwave Electronics products were referenced by non-affiliated inventors in 91 US patents.

Laser welding of polymers is a set of methods used to join polymeric components through the use of a laser. It can be performed using CO2 lasers, Nd:YAG lasers, Diode lasers and Fiber lasers.

References

  1. ↑ "Laser nanofabrication inside silicon with spatial beam modulation and anisotropic seeding". Nat. Commun. 15 (5786). 2024. doi:10.1038/s41467-024-49303-z.
  2. ↑ Wills, Stewart. "Cassini's Earthbound Partners". Optics and Photonics News. The Optical Society. Archived from the original on 7 July 2018. Retrieved 7 July 2018.
  3. ↑ W. Demtröder, Laser Spectroscopy, 3rd Ed. (Springer, 2009)
  4. ↑ "California scientists able to control the weather using lasers - www.express.co.uk". 28 September 2017. Archived from the original on 2018-10-23. Retrieved 2018-10-23.
  5. ↑ "The man who wants to control the weather with lasers - www.cnn.com". CNN . 24 April 2015. Archived from the original on 2018-10-23. Retrieved 2018-10-23.
  6. ↑ "Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment". Phys. Rev. Lett. 132 (6): 065102. doi:10.1103/PhysRevLett.132.065102.
  7. ↑ Duarte FJ, ed. (2009). "Chapter 9". Tunable Laser Applications (2nd ed.). Boca Raton: CRC Press.
  8. ↑ Duarte FJ (2016). "Tunable Laser Microscopy". In Duarte FJ (ed.). Tunable Laser Applications (3rd ed.). Boca Raton: CRC Press. pp. 315–328. ISBN   9781482261066.
  9. ↑ "Thales GLOW". Thalesgroup.com. Archived from the original on 2012-03-23. Retrieved 2011-09-25.
  10. ↑ "Red Dot Sights / Reflex Sights & Holosights Explained". ultimak.com. Archived from the original on 2012-12-27. Retrieved 2013-07-27.
  11. ↑ "The Worldwide Market for Lasers - Market Review and Forecast 2012". Strategies Unlimited. 5th Edition: 56–85. January 2012.
  12. ↑ Sparkes, M.; Gross, M.; Celotto, S.; Zhang, T.; O'Neil, W (2008). "Practical and theoretical investigations into inert gas cutting of 304 stainless steel using a high brightness fiber laser". Journal of Laser Applications. 20 (1042–346X): 59–67. Bibcode:2008JLasA..20...59S. doi: 10.2351/1.2832402 .
  13. ↑ "The Worldwide Market for Lasers - Market Review and Forecast 2012". Strategies Unlimited. 5th Edition: 86–110. January 2012.
  14. ↑ "OLED technology explained". OLED Info. OLED-info.com. Archived from the original on 15 October 2012. Retrieved 17 October 2012.
  15. ↑ "Cinetyp Hollywood - film subtitles, video subtitles, DVD subtitles, film overlay, video, film, overlay, foreign subtitles, closed captioning, open captioning, spotting lists". Cinetyp.com. Archived from the original on 2009-02-28. Retrieved 2009-10-11.
  16. ↑ "SM Cinema Adds Five More Christie 6P Laser Projectors". www.christiedigital.com. Archived from the original on 2017-10-18. Retrieved 2016-11-16.
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