Uses
When lasers were invented in 1960, they were called "a solution looking for a problem". Since then, they have become ubiquitous, finding utility in thousands of highly varied applications in every section of modern society, including consumer electronics, information technology, science, medicine, industry, law enforcement, entertainment, and the military. Fiber-optic communication using lasers is a key technology in modern communications, allowing services such as the Internet.
The first widely noticeable use of lasers was the supermarket barcode scanner, introduced in 1974. The laserdisc player, introduced in 1978, was the first successful consumer product to include a laser but the compact disc player was the first laser-equipped device to become common, beginning in 1982 followed shortly by laser printers.
Some other uses are:
- Communications: besides fiber-optic communication, lasers are used for free-space optical communication, including laser communication in space.
- Medicine: see below.
- Industry: cutting including converting thin materials, welding, material heat treatment, marking parts (engraving and bonding), additive manufacturing or 3D printing processes such as selective laser sintering and selective laser melting, non-contact measurement of parts and 3D scanning, and laser cleaning.
- Military: marking targets, guiding munitions, missile defense, electro-optical countermeasures (EOCM), lidar, blinding troops. See below
- Law enforcement: LIDAR traffic enforcement. Lasers are used for latent fingerprint detection in the forensic identification field
- Research: spectroscopy, laser ablation, laser annealing, laser scattering, laser interferometry, lidar, laser capture microdissection, fluorescence microscopy, metrology, laser cooling.
- Commercial products: laser printers, barcode scanners, thermometers, laser pointers, holograms, bubblegrams.
- Entertainment: optical discs, laser lighting displays, laser turntables
In 2004, excluding diode lasers, approximately 131,000 lasers were sold with a value of US$2.19 billion. In the same year, approximately 733 million diode lasers, valued at $3.20 billion, were sold.
In medicine
Lasers have many uses in medicine, including laser surgery (particularly eye surgery), laser healing, kidney stone treatment, ophthalmoscopy, and cosmetic skin treatments such as acne treatment, cellulite and striae reduction, and hair removal.
Lasers are used to treat cancer by shrinking or destroying tumors or precancerous growths. They are most commonly used to treat superficial cancers that are on the surface of the body or the lining of internal organs. They are used to treat basal cell skin cancer and the very early stages of others like cervical, penile, vaginal, vulvar, and non-small cell lung cancer. Laser therapy is often combined with other treatments, such as surgery, chemotherapy, or radiation therapy. Laser-induced interstitial thermotherapy (LITT), or interstitial laser photocoagulation, uses lasers to treat some cancers using hyperthermia, which uses heat to shrink tumors by damaging or killing cancer cells. Lasers are more precise than traditional surgery methods and cause less damage, pain, bleeding, swelling, and scarring. A disadvantage is that surgeons must have specialized training. It may be more expensive than other treatments.
As weapons
 | This article should include a summary of Laser weapon. (December 2019) |
A laser weapon is a laser that is used as a directed-energy weapon.
Hobbies
In recent years, some hobbyists have taken interests in lasers. Lasers used by hobbyists are generally of class IIIa or IIIb (see Safety), although some have made their own class IV types. However, compared to other hobbyists, laser hobbyists are far less common, due to the cost and potential dangers involved. Due to the cost of lasers, some hobbyists use inexpensive means to obtain lasers, such as salvaging laser diodes from broken DVD players (red), Blu-ray players (violet), or even higher power laser diodes from CD or DVD burners.
Hobbyists also have been taking surplus pulsed lasers from retired military applications and modifying them for pulsed holography. Pulsed Ruby and pulsed YAG lasers have been used.
Examples by power
Different applications need lasers with different output powers. Lasers that produce a continuous beam or a series of short pulses can be compared on the basis of their average power. Lasers that produce pulses can also be characterized based on the peak power of each pulse. The peak power of a pulsed laser is many orders of magnitude greater than its average power. The average output power is always less than the power consumed.
| Power | Use |
|---|---|
| 1–5 mW | Laser pointers |
| 5 mW | CD-ROM drive |
| 5–10 mW | DVD player or DVD-ROM drive |
| 100 mW | High-speed CD-RW burner |
| 250 mW | Consumer 16× DVD-R burner |
| 400 mW | Burning through a jewel case including disc within 4 seconds |
| DVD 24× dual-layer recording | |
| 1 W | Green laser in Holographic Versatile Disc prototype development |
| 1–20 W | Output of the majority of commercially available solid-state lasers used for micro machining |
| 30–100 W | Typical sealed CO2 surgical lasers |
| 100–3000 W | Typical sealed CO2 lasers used in industrial laser cutting |
Examples of pulsed systems with high peak power:
- 700 TW (700×1012 W) – National Ignition Facility, a 192-beam, 1.8-megajoule laser system adjoining a 10-meter-diameter target chamber
- 1.3 PW (1.3×1015 W) – world's most powerful laser as of 1998, located at the Lawrence Livermore Laboratory
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