 A keychain laser pointer. A laser pointer is a portable, pen-sized laser designed to be held in the hand, and most commonly used to project a point of light to highlight items of interest during a presentation. Most laser pointers have low enough power that the projected beam is not visible from the side in normal clear air, but is only visible as a point of light where the beam strikes a diffusely reflective surface. Some higher powered laser pointers are visible via Rayleigh scattering when viewed from the side in moderately to dimly lit conditions. Download high resolution version (954x488, 63 KB) Laser Pointer File links The following pages link to this file: Laser pointer Categories: Public domain images ...
Download high resolution version (954x488, 63 KB) Laser Pointer File links The following pages link to this file: Laser pointer Categories: Public domain images ...
Experiment with a laser (US Military) In physics, a laser is a device that emits light through a specific mechanism for which the term laser is an acronym: Light Amplification by Stimulated Emission of Radiation. ...
Street preacher in Covent Garden using a presentation style Presentation is the process of presenting the content of a topic to an audience. ...
Rayleigh scattering causing the blue hue of the sky and the reddening at sunset Rayleigh scattering (named after Lord Rayleigh) is the scattering of light, or other electromagnetic radiation, by particles much smaller than the wavelength of the light. ...
Types of laser pointer Most inexpensive laser pointers use a deep red laser diode near 670/650 nm wavelength. Slightly more expensive ones use a brown-orange 635 nm diode, making them more easily visible than their 670 nm counterparts due to the greater sensitivity of the human eye at 635 nm. Other colors are possible too, with the 532 nm green laser being the most common alternative. In the past few years, yellow-orange laser pointers, at 593.5 nm, have been made available. Recently (September 2005), handheld blue laser pointers at 473 nm have also become available. A packaged laser diode with penny for scale. ...
A nanometre (American spelling: nanometer) is 1. ...
The wavelength is the distance between repeating units of a wave pattern. ...
Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ...
The apparent brightness of a spot from a laser beam depends not only on the optical power of the laser and the reflectivity of the surface, but also on the color response of the human eye. For the same optical power, the green laser will seem brighter than other colors because the human eye is most sensitive in the green area of spectrum (for low light levels), with sensitivity decreasing as colors become redder or bluer. For other uses, see Eye (disambiguation). ...
The output power of a laser pointer is measured in milliwatts (mW). In Europe/UK the legal requirement is that laser pointer output not exceed 1 mW; in USA this output is limited to 5 mW for presentation lasers. All laser products offered in commerce in the US must be registered with the US FDA, regardless of output power.[citation needed] Milliwatt (SI symbol: mW) is a unit for measuring electrical power, equal to one-thousandth (10-3) of a watt. ...
Street preacher in Covent Garden using a presentation style Presentation is the process of presenting the content of a topic to an audience. ...
hi “FDA†redirects here. ...
Green laser pointer
 A 5 mW green laser pointer directed at a palm tree at night. Note that the beam itself is visible through Rayleigh scattering and airborne dust. Green laser pointers[1] appeared on the market circa 2000, and are the most common type of DPSS lasers (also called DPSSFD, diode pumped solid state frequency-doubled). They are much more complicated than standard red laser pointers, since laser diodes are not commonly available in this wavelength range. The green light is generated in an indirect process, beginning with a high-power (typically 100-300 mW) infrared AlGaAs laser diode operating at 808 nm. The 808 nm light pumps a crystal of Neodymium-doped Vanadate (or Nd:YAG or less common Nd:YLF), which lases deeper in the infrared at 1064 nm. The vanadate crystal is coated on the diode side with a dielectric mirror that reflects at 1064 nm and transmits at 808 nm. The crystal is mounted on a copper block, acting as a heatsink; its 1064 nm output is fed into a crystal of potassium titanyl phosphate (KTP), mounted on a heatsink in the laser cavity resonator. The orientation of the crystals must be matched, as they are both anisotropic and the Nd:YVO4 outputs polarized light. This unit acts as a frequency doubler, and halves the wavelength to the desired 532 nm. The resonant cavity is terminated by a dielectric mirror that reflects at 1064 nm and transmits at 532 nm. An infrared filter behind the mirror removes IR radiation from the output beam, and the assembly ends in a collimator lens. The output power of most green laser pointers is on the order of 5 mW. In 2007, the Guinness Book of World Records published a new world record called "Most Powerful Handheld Laser" which was awarded to Wicked Lasers for their Spyder Series Laser Pointer. [2] Image File history File linksMetadata Size of this preview: 800 × 600 pixel Image in higher resolution (1024 × 768 pixel, file size: 227 KB, MIME type: image/jpeg) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
Image File history File linksMetadata Size of this preview: 800 × 600 pixel Image in higher resolution (1024 × 768 pixel, file size: 227 KB, MIME type: image/jpeg) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
Rayleigh scattering causing the blue hue of the sky and the reddening at sunset Rayleigh scattering (named after Lord Rayleigh) is the scattering of light, or other electromagnetic radiation, by particles much smaller than the wavelength of the light. ...
Diode-pumped solid-state (DPSS) lasers are solid-state lasers made by pumping a solid gain medium, for example, a ruby or a neodymium-doped YAG crystal, with a laser diode. ...
A packaged laser diode with penny for scale. ...
Image of two girls 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 radio waves. ...
Aluminium gallium arsenide (also Aluminum gallium arsenide) (AlxGa1-xAs) is a semiconductor material with very nearly the same lattice constant as GaAs, but a larger bandgap. ...
Laser pumping is the act of energy transfer from an external source into the laser gain medium. ...
Yttrium aluminium garnet (YAG, Y3Al5O12) is a synthetic crystalline material of the garnet group, used as the active laser medium in various solid-state lasers. ...
Neodymium-doped yttrium lithium fluoride (Nd:YLF) is a lasing medium for arclamp-pumped and diode-pumped solid-state lasers. ...
A dielectric mirror is a special kind of a mirror. ...
For other uses, see Copper (disambiguation). ...
A large copper heatsink. ...
Potassium titanyl phosphate (KTiOPO4) or KTP is a nonlinear optical material which is commonly used for frequency doubling diode pumped solid-state lasers such as Nd:YAG and other neodymium-doped lasers. ...
To meet Wikipedias quality standards, this article or section may require cleanup. ...
This article is being considered for deletion in accordance with Wikipedias deletion policy. ...
This article treats polarization in electrodynamics. ...
Second Harmonic Generation (SHG) is a subcategory of nonlinear optics in physics. ...
How a lead collimator filters a stream of rays. ...
Nd:YVO4 is replacing Nd:YAG and Nd:YLF due to lower dependency on the exact parameters of the pump diode (therefore allowing for higher tolerances), wider absorption band, lower lasing threshold, higher slope efficiency, linear polarization of output light, and single mode output.[3] For frequency doubling of higher power lasers, LBO is used instead of KTP. Newer lasers use a composite Nd:YVO4/KTP crystal instead of two discrete ones. In optics, the lasing threshold is the lowest excitation level at which laser output is dominated by stimulated emission rather than by spontaneous emission. ...
The slope efficiency is an important property of a laser. ...
In electrodynamics, linear polarization or plane polarization of electromagnetic radiation is a confinement of the electric field vector or magnetic field vector to a given plane along the direction of propagation. ...
Lithium triborate (LiB3O5, or LBO) is a non-linear optics crystal. ...
Potassium titanyl phosphate (KTiOPO4) or KTP is a nonlinear optical material which is commonly used for frequency doubling diode pumped solid-state lasers such as Nd:YAG and other neodymium-doped lasers. ...
Some green lasers operate in pulse or quasi-continuous-wave (QCW) mode, to reduce cooling problems and prolong battery life.
Blue laser -
Blue laser pointers, which became available circa 2006, have the same basic construction as green lasers. They most often lase at 473 nm, which is produced by frequency doubling of 946 nm laser radiation from a diode-pumped Nd:YAG or Nd:YVO4 crystal. In 2006 many factories began production of Blue Laser Diodes for mass storage devices such as Blu-ray entering the mass consumer market. This may result in massive drops in prices of Blue Laser Pointers as the diodes become available for the laser pointer market during 2007/8. For high output power BBO crystals are used as frequency doublers, for lower powers KTP is used. Blue lasers have applications in many areas, from opto-electronic data storage at high-density, to medical applications. ...
Acronym for Neodymium-doped Yttrium Aluminum Garnet, a compound that is used as the lasing medium for certain solid-state lasers. ...
Blu-ray discs Blu-ray Disc is a next-generation optical disc format jointly developed by a group of leading consumer electronics and PC companies called the Blu_ray Disc Association (BDA), which succeeds the Blu_ray Disc Founders (BDF). ...
Beta barium borate (β-barium borate, BBO or β-BaB2O4) is a crystal frequently used for frequency mixing and other nonlinear optics applications. ...
Potassium titanyl phosphate (KTiOPO4) or KTP is a nonlinear optical material which is commonly used for frequency doubling diode pumped solid-state lasers such as Nd:YAG and other neodymium-doped lasers. ...
Blue lasers can also be fabricated with InGaN semiconductors. In this case, no frequency doubler is needed. The Japanese company Nichia controls (in 2006) 80% of the market. [citation needed]
Applications Laser pointers are often used in school and business presentations and visual demonstrations as an eye-catching pointing device. Red laser pointers can be used in almost any indoor or low-light situation where pointing out details by hand may be inconvenient, such as in construction work or interior decorating. Green laser pointers can be used for similar purposes as well as outdoors in daylight or for longer distances. Street preacher in Covent Garden using a presentation style Presentation is the process of presenting the content of a topic to an audience. ...
This article does not cite any references or sources. ...
 A laser pointer in operation, shown in light and darkness. In pointing applications such as these, natural hand tremor may cause unwanted jittery motion of the laser dot. Future laser pointers may solve this problem by stabilizing the laser beam from unwanted hand tremor.[4] Laser pointer in operation (in the bright light and in the dark) File links The following pages link to this file: Laser pointer Categories: Public domain images ...
Laser pointer in operation (in the bright light and in the dark) File links The following pages link to this file: Laser pointer Categories: Public domain images ...
For the film see Tremors (film). ...
Laser pointers can be used as toys for pets, especially for cats in play. Some offer a selection of designs for the laser beam to project (e.g. images of butterflies, mice, or flowers), to provide variety. Opinions are divided on the safety of laser pointers used in this way. Some consider laser pointers to be a healthier alternative to the more traditional string for cats because they reduce the risk of choking on the string. Others are concerned that the laser beam may damage pets' eyes, or that the pet will develop frustration problems from not being able to catch the prey. [5] It has been suggested that Residential pets be merged into this article or section. ...
Binomial name Felis catus Linnaeus, 1758 Synonyms Felis lybica invalid junior synonym The cat (or domestic cat, house cat) is a small carnivorous mammal. ...
Laser pointers do not function as laser sights, although they may appear to be similar to sighting lasers at first impression. There are many scientific, military, medical and commercial laser applications which have been developed since the invention of the laser in the 1958. ...
Green laser pointers can also be used for skygazing. On a moonless night, a green laser pointer beam can often be clearly seen, allowing someone to accurately point out individual stars to others nearby. This article or section needs copy editing for grammar, style, cohesion, tone and/or spelling. ...
Hazards -
Laser pointers should never be directed into the eyes of a person or animal or into any moving vehicle in which the driver or pilot could be distracted. The output of laser pointers is generally limited to 1 mW or 5 mW[citation needed] in order to prevent accidental damage to the retina of human eyes. Usually, pen lasers are class 2 or class 3a lasers, which require extended viewing times to damage the retina severely. There is some debate about whether outputs of 5 mW may damage eyes if viewed through spectacles or contact lenses.[citation needed] The Food and Drug Administration (FDA) has determined that Class 3a lasers could cause injury to the eye if viewed directly for approximately 0.25 seconds, although it has cited evidence that exposure to visible lasers is "usually" limited by the blink reflex of the eye, which they have timed at just under 0.25 seconds.[citation needed] A typical laser warning symbol. ...
Under certain conditions, laser light or other bright lights (spotlights, searchlights) directed at aircraft can be a hazard. ...
Human eye cross-sectional view. ...
For other uses, see Eye (disambiguation). ...
hi “FDA†redirects here. ...
This article refers to the sight organ. ...
In the late 1990s, the laser pointer became a fad amongst adolescents as an irritant to be pointed stealthily at a movie theater screen or even at a person's eyes. During late 2004 a man was arrested in USA under terrorist laws when he was identified as pointing a high power green laser pointer into the cockpit of an airplane.[6]
Despite legislation limiting the output of laser pointers in some countries (such as the USA and Australia), higher-power devices are currently produced in other regions (especially China and Hong Kong), and are frequently imported by customers who purchase them directly via internet mail order. The legality of such transactions is not always clear; typically, the lasers are sold as research or OEM devices (which are not subject to the same power restrictions), with a disclaimer that they are not to be used as pointers. These lasers are known as "Wicked Lasers", from the name of the first company to mass market high powered green laser pointers (up to 45mW) in 2003. As the popularity of these hazardous devices soared, many manufacturers (mainly in China) began manufacturing similar high powered pointers. The FDA has published a warning on the dangers of such high powered lasers[7]. Despite the disclaimers, such Wicked Lasers are frequently sold in packaging resembling that for laser pointers. Lasers of this type may not include safety features sometimes found on laser modules sold for research purposes. Original equipment manufacturer, or OEM, is a term that refers to a situation in which one company purchases a manufactured product from another company and resells the product as its own, usually as a part of a larger product it sells. ...
In Utah it is a class C misdemeanor to point a laser pointer at a law enforcement officer and is an infraction to point a laser pointer at a moving vehicle.[8] This article is about the U.S. state. ...
A misdemeanor, or misdemeanour, in many common law legal systems, is a lesser criminal act. ...
For the band, see The Police. ...
For the similarly written medical term referring to a blocked artery, see infarction. ...
As powerful handheld green lasers become more popular in today's market, it has become known that irresponsible use of higher powered green lasers can be disastrous. Experts say that a direct shot to the eye from a laser over 65 mW can permanently damage the eye within a fraction of a second.[citation needed] The risk becomes greater with more powerful lasers, which are readily available on the internet today.
If used to play with animals, lasers with power output less than 0.5 mW are recommended,[citation needed] although some animals will not respond to lasers with this low power level when used in bright sunlight or similar situations producing low contrast laser point images.
High-powered portable lasers In recent years, high-powered portable lasers have come on the market from a number of specialized suppliers. These lasers can exceed several hundred mW in output. Because those are Class IIIB lasers (larger than 5 mW), they are not true "laser pointers" by legal definition, although hobbyists still refer to them as "pointers."
Many Class IIIB portable lasers incorporate safety features and interlocks not found on a standard, low-power laser pointer. These may include a safety dongle and/or safety key, an aperture shutter, a power indicator light, and an emission delay of two or three seconds.
See also Image File history File links Nuvola_apps_ksim. ...
A typical laser warning symbol. ...
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