Laser pointer
The US FDA Code of Federal Regulations stipulates that "demonstration laser products" such as pointers must comply with applicable requirements for Class I, II, IIIA, IIIB, or IV devices.
The green light is generated through a multi-step process, usually beginning with a high-power (typically 100–300 mW) infrared aluminium gallium arsenide (AlGaAs) laser diode operating at 808 nm.
Some green lasers operate in pulse or quasi-continuous wave (QCW) mode to reduce cooling problems and prolong battery life.
An announcement in 2009[7] of a direct green laser (which does not require doubling) promises much higher efficiencies and could foster the development of new color video projectors.
Because even a low-powered green laser is visible at night through Rayleigh scattering from air molecules, this type of pointer is used by astronomers to easily point out stars and constellations.
The 5 mW green laser pointers (classes II and IIIa) are the safest to use, and anything more powerful is usually not necessary for pointing purposes, since the beam is still visible in dark lighting conditions.
[12] 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.
[13] Green lasers are visible at night due to Rayleigh scattering and airborne dust,[14] allowing someone to point out individual stars to others nearby.
For instance, construction companies may use high quality laser pointers to enhance the accuracy of showing specific distances, while working on large-scale projects.
[1] The output of laser pointers available to the general public is limited (and varies by country) in order to prevent accidental damage to the retina of human eyes.
Studies have found that even low-power laser beams of not more than 5 mW can cause permanent retinal damage if gazed at for several seconds; however, the eye's blink reflex must be intentionally overcome to make this occur.
Studies in the early twenty-first century found that the risk to the human eye from accidental exposure to light from commercially available class IIIa laser pointers having powers up to 5 mW seemed rather small; however, prolonged viewing, such as deliberate staring into the beam for 10 or more seconds, can cause damage.
[27][28][29][30] The UK Health Protection Agency warns against the higher-power typically green laser pointers available over the Internet, with power output of up to a few hundred milliwatts, as "extremely dangerous and not suitable for sale to the public.
These potentially hazardous lasers produce little or no visible beam when shone through the eyewear supplied with them, yet their IR-laser output can still be easily seen when viewed with an IR-sensitive video camera.
The very bright, small spot makes it possible to dazzle and distract drivers and aircraft pilots, and they can be dangerous to sight if aimed at the eyes.
After performing the song, Criss nearly stormed off the stage, and lead singer Paul Stanley ripped into whoever had been manipulating the laser light: In every crowd, there's one or two people who don't belong [...] Now I know you want to [take] it to school tomorrow when you go to sixth grade, but [you should have left] it at home [before coming] to the show.According to FIFA stadium safety and security regulations, laser pointers are prohibited items at stadiums during FIFA football tournaments and matches.
[39] At the 2014 World Cup during the final group stage match between Algeria and Russia a green laser beam was directed on the face of Russian goalkeeper Igor Akinfeev.
[42] Despite legislation limiting the output of laser pointers in some countries, higher-power devices are currently produced in other regions 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.
[44] In April 2008, citing a series of coordinated attacks on passenger jets in Sydney, the Australian government announced that it would restrict the sale and importation of certain laser items.
[46] In Victoria and the Australian Capital Territory a laser pointer with an accessible emission limit greater than 1 mW is classified as a prohibited weapon and any sale of such items must be recorded.
Canadian federal regulation follows FDA (US Food & Drug Administration) CDRH, and IEC (International Electrotechnical Commission) hazard classification methods where manufacturers comply with the Radiation Emitting Devices Act.
As of July 2011 three people[55] had been charged under the federal Aeronautics Act, which carries a maximum penalty of $100,000 and five years in prison, for attempting to dazzle a pilot with a laser.
[56] The "RESOLUCIÓN 57151 DE 2016" prohibits the marketing and making available to consumers of laser pointers with output power equal to or greater than one milliwatt (>=1 mW).
Laser pointers are not illegal in Hong Kong but air navigation rules state that it is an offense to exhibit "any light" bright enough to endanger aircraft taking off or landing.
On August 6, 5 off-duty police officers arrested Baptist University student union president Keith Fong Chung-yin after he purchased 10 laser pointers in Sham Shui Po for possession of "offensive weapons".
Human rights activist Icarus Wong Ho-yin said that going by the police explanation, “a kitchen worker who buys a few knives can be arrested for being in possession of offensive weapons”.
In 1998 it became illegal to trade Class 2 laser pointers that are "gadgets" (e.g. ball pens, key chains, business gifts, devices that will end up in children's possession, parts of toys, etc.).
(Arizona Revised Statutes §13-1213) [70] Public act 257 of 2003 makes it a felony for a person to "manufacture, deliver, possess, transport, place, use, or release" a "harmful electronic or electromagnetic device" for "an unlawful purpose"; also made into a felony is the act of causing "an individual to falsely believe that the individual has been exposed to a... harmful electronic or electromagnetic device.
"[71] Public act 328 of 1931 makes it a felony for a person to "sell, offer for sale, or possess" a "portable device or weapon from which an electric current, impulse, wave, or beam may be directed" and is designed "to incapacitate temporarily, injure, or kill".
