Green laser pointers

Green laser pointers were first commercially sold in the year 2000. They operate at the wavelength of 532 nm. Laser diodes of this wavelength are not available so the green light is obtained by the use of "DPSSFD" laser technology.
The process:-
A very high-powered Infrared laser diode working at 808 nm pumps a tiny block of Nd: YVO4 that generates light at 1,064 nm. This feeds a potassium titanyl phosphate intracavity frequency doubler crystal that produces green light of a visible 532 nm wavelength. High-powered green lasers use lithium triborate instead of KTP.
Features:-
An infrared filter, which is behind the mirror completely, removes the radiation of infrared spectrum from the output beam. In order to reduce cooling problems and prolong battery life, some green lasers operate in pulse or quasi-continuous-wave (QCW) mode. The Class III a laser product gives an output power of 5mw. This is the one of highest-powered street legal laser. Some green lasers even have an output of 10 mw, which has a range of 20,000 feet in darkness. Some even have a 3-second delay feature as these are high-powered lasers and can blind a person. Some laser point extenders are also available. They work by using lenses to minimize the beam spread of a laser. Its price starts from 55$. Majority of them have a life of around 3000 hours.
Applications:-
Green lasers can be used for a variety of roles. They can be used as pointing devices. The ability to form a continuous line in the dark is an added advantage; this has lead to its usage as rescue lights as it can be seen from miles away. It as been used for laser light shows. It is also used for sky gazing as a person can pinpoint a star by using the green laser. It can also be as laser pointers for guns, rifles. In the movie Alien vs. Predator it was used as a pointing device on some G36k carbines.
Advantages:-
The green laser has many advantages. It is fifty times brighter than a red laser because of which it can be seen from miles away, this helps in being rescued if a person is lost. It can also be used in high-tech weapons for aiming purposes. Because of its high range, Green laser pointers can be equipped in different kinds of weapons. High and low temperatures do not affect the performance of Green laser pointers so in case a person is lost in a desert, he can still use Green laser pointers to call for help, in other case, even if a person is lost some where in mountains all covered with ice, he can still use it.
Disadvantages:-
Due to its high power it can permanently damage a person's eye. As it can form a continuous line of light that might reveal a person's position so it cannot be used in stealthy operations or by SWAT.
Green laser is quite awesome but it should be used carefully.

By:- Amit Samantaray