定义：
按照激光探头是否与激光作用的物质接触，分为接触式和非接触式两种工作模式。激光应用的领域，主要有工业、医疗、商业、科研、信息和军事六个领域。工业应用中，主要有材料加工和测量控制；医疗应用，有治疗和诊断；商业应用

激光历史
世界上第一台激光器诞生于1960年，中国于1961年研制出第一台激光器，40多年来，激光技术与应用发展迅猛，已与多个学科相结合形成多个应用技术领域，
比如光电技术，激光医疗与光子生物学，激光加工技术，激光检测与计量技术，激光全息技术，激光光谱分析技术，非线性光学，超快激光学，激光化学，量子光学，激光雷达，激光制导，激光分离同位素，激光可控核聚变，激光武器等等。这些交叉技术与新的学科的出现，大大地推动了传统产业和新兴产业的发展。

日常应用
激光指示
激光指示器，又称为激光笔、指星笔等，是把可见激光设计成便携、手易握、激光模组（二极管）加工成的笔型发射器。常见的激光指示器有红光(650-660nm)、绿光(532nm)和蓝紫光(405nm)等。

通常在会报、教学、导赏人员都会使用它来投映一个光点或一条光线指向物体，但它可能会破坏或影响导览物的场所，例如艺术馆（有些画作怕光）、动物园等都不宜使用。

加工技术
激光加工技术是利用激光束与物质相互作用的特性对材料(包括金属与非金属)进行切割、焊接、表面处理、打孔、微加工以及做为光源，识别物体等的一门技术，传统应用最大的领域为激光加工技术。激光技术是涉及到光、机、电、材料及检测等多门学科的一门综合技术，传统上看，它的研究范围一般可分为：加工系统包括激光器、导光系统、加工机床、控制系统及检测系统。

加工工艺
包括切割、焊接、表面处理、打孔、打标、划线、微调等各种加工工艺。
激光焊接：汽车车身厚薄板、汽车零件、锂电池、心脏起搏器、密封继电器等密封器件以及各种不允许焊接污染和变形的器件。目前使用的激光器有YAG激光器，CO2激光器和半导体泵浦激光器。

激光切割：汽车行业、计算机、电气机壳、木刀模业、各种金属零件和特殊材料的切割、圆形锯片、压克力、弹簧垫片、2mm以下的电子机件用铜板、一些金属网板、钢管、镀锡铁板、镀亚铅钢板、磷青铜、电木板、薄铝合金、石英玻璃、硅橡胶、1mm以下氧化铝陶瓷片、航天工业使用的钛合金等等。使用激光器有YAG激光器和CO2激光器。

激光打标：在各种材料和几乎所有行业均得到广泛应用，目前使用的激光器有YAG激光器、CO2激光器和半导体泵浦激光器。
激光打孔：激光打孔主要应用在航空航天、汽车制造、电子仪表、化工等行业。激光打孔的迅速发展，主要体现在打孔用YAG激光器的平均输出功率已由5年前的400w提高到了800w至1000w。

国内目前比较成熟的激光打孔的应用是在人造金刚石和天然金刚石拉丝模的生产及钟表和仪表的宝石轴承、飞机叶片、多层印刷线路板等行业的生产中。目前使用的激光器多以YAG激光器、金运CO2激光器为主，也有一些准分子激光器、同位素激光器和半导体泵浦激光器。

激光热处理：在汽车工业中应用广泛，如缸套、曲轴、活塞环、换向器、齿轮等零部件的热处理，同时在航空航天、机床行业和其它机械行业也应用广泛。我国的激光热处理应用远比国外广泛得多。目前使用的激光器多以YAG激光器，CO2激光器为主。

激光快速成型：将激光加工技术和计算机数控技术及柔性制造技术相结合而形成。多用于模具和模型行业。目前使用的激光器多以YAG激光器、CO2激光器为主。

激光涂敷：在航空航天、模具及机电行业应用广泛。目前使用的激光器多以大功率金运YAG激光器、金运CO2激光器为主。

生物应用
       2014年6月，美国科学家，开发出了可以快速控制果蝇思想的激光系统。系统名为蝇类思维转换装置(缩写FlyMAD)，系统通过摄像头追踪有限空间内若干果蝇的动作，研究人员通过向果蝇发射特殊调谐激光，可以触发果蝇大脑内与光热有关的神经通路。
       希望将光遗传学和热遗传学指令相结合，在未来可以对果蝇进行更为深入的控制。值得庆幸的是相同的技术对人类复杂的大脑结构没有效果。果蝇是研究光控思维的理想实验对象，FlyMAD试验中所用果蝇都是基因改造过后的品种，非常适合实验需求。
       科学家可以指挥果蝇跳月球步并不意味着某天某人对你眼中照射一束光线你就会情不自禁地在舞池中翩翩起舞，所以不用担心啦，至少目前是不可能的。

Definition: applications involving laser devices

Lasers are sources of light with very special properties, as discussed in the article on laser light. For that reason, there is a great variety of laser applications, leading to a total of over 8 billion USD of global laser sales (as of 2013). The following sections give a brief overview.

Laser-aided Manufacturing

Lasers are widely used for laser material processing in manufacturing, e.g. for cutting, drilling, welding, cladding, soldering (brazing), hardening, surface modification, marking, engraving, micromachining, pulsed laser deposition, lithography, etc. In many cases, relatively high optical intensities are applied to a small spot, leading to intense heating, possibly evaporation and plasma generation. Essential aspects are the high spatial coherence of laser light, allowing for strong focusing, and often also the potential for generating intense pulses.

Laser processing methods have many advantages, compared with mechanical approaches. They allow the fabrication of very fine structures with high quality, avoiding mechanical stress such as caused by mechanical drills and blades. A laser beam with high beam quality can be used to drill very fine and deep holes, e.g. for injection nozzles. A high processing speed is often achieved, e.g. in the fabrication of filter sieves. Further, the lifetime limitation of mechanical tools is removed. It can also be advantageous to process materials without touching them.

The requirements on optical power and beam quality apart from the wavelength depend very much on the application and the involved materials. For example, laser marking on plastics can be done with fairly low power levels, whereas cutting, welding or drilling on metals requires much more – often multiple kilowatts. Soldering applications may require a high power but only a moderate beam quality, whereas particularly remote welding (i.e., welding with a substantial distance between laser head and welded parts) depends on a high beam quality.

Laser-aided manufacturing often allows one to produce the essentially same parts with higher quality and/or lower cost. Also, it is often possible to realize entirely new part designs or the use of new materials. For example, automobile parts are increasingly made of light materials such as aluminum, which require tentatively more laser joining operations. Weight reductions are possible not only by the user of lighter materials, but also e.g. by producing them with shorter flanges due to higher precision than is feasible with conventional production methods.

Lasers are also widely used for alignment purposes. Alignment lasers may simply emit a Gaussian laser beam, forming a circular spot on a workpiece, a line, a cross, or some other pattern. They are important for many manufacturing processes.

Medical Applications

There is a wide range of medical applications. Often these relate to the outer parts of the human body, which are easily reached with light; examples are eye surgery and vision correction (LASIK), dentistry, dermatology (e.g. photodynamic therapy of cancer), and various kinds of cosmetic treatment such as tattoo removal and hair removal.

Lasers are also used for surgery (e.g. of the prostate), exploiting the possibility to cut tissues while causing minimal bleeding. Some operations can be done with endoscopic means; an endoscope may contain an optical fiber for delivering light to the operation scene and another fiber for imaging, apart from additional channels for mechanical instruments.

Very different types of lasers are required for medical applications, depending on the optical wavelength, output power, pulse format, etc. In many cases, the laser wavelength is chosen such that certain substances (e.g. pigments in tattoos or caries in teeth) absorb light more strongly than surrounding tissue, so that they can be more precisely targeted.

Medical lasers are not always used for therapy. Some of them rather assist the diagnosis, e.g. via methods of ocular imaging, laser microscopy or laser spectroscopy (see below).

For more details, see the article on medical lasers.

Metrology

Lasers are widely used in optical metrology, e.g. for extremely precise position measurements and optical surface profiling with interferometers, for long-distance range finding and navigation.

Laser scanners are scanning the direction of laser beams, which can read e.g. bar codes or other graphics over some distance. It is also possible to scan three-dimensional objects, e.g. in the context of crime scene investigation (CSI).

Optical sampling is a technique applied for the characterization of fast electronic microcircuits, microwave photonics, terahertz science, etc.

Lasers also allow for extremely precise time measurements and are therefore essential component of optical clocks which are beginning to outperform the currently used cesium atomic clocks.

Fiber-optic sensors, often probed with laser light, allow for the distributed measurement of temperature, stress, and other quantities e.g. in oil pipelines and wings of airplanes.

Data Storage

Optical data storage e.g. in compact disks (CDs), DVDs, Blu-ray Discs and magneto-optical disks, nearly always relies on a laser source, which has a high spatial coherence and can thus be used to address very tiny spots in the recording medium, allowing a very high density data storage. Another case is holography, where the temporal coherence can also be important.

Communications

Optical fiber communication, extensively used particularly for long-distance optical data transmission, mostly relies on laser light in optical glass fibers. Free-space optical communications, e.g. for inter-satellite communications, is based on higher-power lasers, generating collimated laser beams which propagate over large distances with small beam divergence.

One may also transmit analog RF and microwave signals using radio and microwave over fiber technology.

Displays

Laser projection displays containing RGB sources can be used for cinemas, home videos, flight simulators, etc., and are often superior to other displays concerning possible screen dimensions, resolution and color saturation. However, further reductions in manufacturing costs will be essential for deep market penetration.

Laser Spectroscopy

Laser spectroscopy is used in many different forms and in a wide range of applications. For example, atmospheric physics and pollution monitoring profits from trace gas sensing with differential absorption LIDAR technology. Solid materials can be analyzed with laser-induced breakdown spectroscopy. Laser spectroscopy also plays a role in medicine (e.g. cancer detection), biology, and various types of fundamental research, partly related to metrology (see above).

Microscopy

Laser microscopes and setups for optical coherence tomography (OCT) provide images of, e.g., biological samples with very high resolution, often in three dimensions. It is also possible to realize functional imaging.

Various Scientific Applications

Laser cooling makes it possible to bring clouds of atoms or ions to extremely low temperatures. This has applications in fundamental research and also for industrial purposes.

Particularly in biological and medical research, optical tweezers can be used for trapping and manipulating small particles, such as bacteria or parts of living cells.

Laser guide stars are used in astronomical observatories in combination with adaptive optics for atmospheric correction. They allow substantially increased image resolution even in cases where a sufficiently close-by natural guide star is not available.

Energy Technology

In the future, high-power laser systems might play a role in electricity generation. Laser-induced nuclear fusion is investigated as a alternative to other types of fusion reactors. High-power lasers can also be used for isotope separation.

Military Applications

There are a variety of military laser applications. In relatively few cases, lasers are used as weapons; the “laser sword” has become popular in movies, but not in practice. Some high-power lasers are currently developed for potential use as directed energy weapons on the battle field, or for destroying missiles, projectiles and mines.

In other cases, lasers function as target designators or laser sights (essentially laser pointers emitting visible or invisible laser beams), or as irritating or blinding (normally not directly destroying) countermeasures e.g. against heat-seeking anti-aircraft missiles. It is also possible to blind soldiers temporarily or permanently with laser beams, although the latter is forbidden by rules of war.

There are also many laser applications which are not specific for military use, e.g. in areas such as range finding, LIDAR, and optical communications.