subject: Laser Pointers Have Many Colors On The Market [print this page] It is well known that laser pointer is a potent signaling tool that can produce bright signals in daylight for potential search and rescue vehicles. It is called as an emergency kit since you can use it to make clear light when you get into dangerous situation so that others can find you. It is very useful in such a kind situation. If you want to go out for adventure, take a laser pointer in case of accident and emergency.
A laser pointer or laser pen is a small handheld device with a power source (usually a battery) and a laser diode emitting a very narrow coherent low-powered laser beam of visible light, intended to be used to highlight something of interest by illuminating it with a small bright spot of colored light. The small width of the beam and low power of typical laser pointers make the beam itself invisible in a reasonably clean atmosphere, only showing a point of light when striking an opaque surface. Some higher-powered laser pointers project a visible beam via scattering from dust particles or water droplets along the beam path. Higher-power and higher-frequency green or blue lasers may produce a beam visible even in clean air because of Rayleigh scattering from air molecules, especially when viewed in moderately-to-dimly lit conditions. There are much type of colors, such as Red and red-orange, Yellow, Green, and Green and so on. Each of then has different features. For example, the red and red-orange laser pointer is one of the most common and simplest pointers, since the laser diodes are available in these wavelengths. The first red laser pointer came out in early 1980s, with large appearance, but very expensive. Nowadays, it is smaller than before and very cheap if you buy it from online shop. Yellow laser pointer is available in recent years with emission of about 600nm. Green laser pointers appeared on the market circa 2000, and are the most common type of DPSS lasers (also called DPSSFD for "diode pumped solid state frequency. Some green lasers operate in pulse or quasi-continuous wave (QCW) mode, to reduce cooling problems and prolong battery life. An announcement in 2009 of a direct green laser (which does not requiring doubling) promises much higher efficiencies and could foster the development of new color video projectors. Blue laser pointer has emission of about 500nm which is usually having the same basic constructions as DPSS green lasers.
It became common in recent years. If you aim the laser pointers at your eyes, it will give raise to temporary disturbances to vision. Although there is some evidence of rare minor permanent harm, it is proved that low-powered laser pointers are not seriously hazardous to health actually. Some times, they may be a major annoyance in some circumstances. From my part, the green beam laser pointer have advantages features than disadvantages. You will not get hurt as long as you use it with the correct way. After all, besides make the light, it can also save your life when you are in emergency.
