subject: How much do you know about green laser pointer? [print this page] How much do you know about green laser pointer?
Nowadays, I am quite interested in technology and science. And laser pointer of course became one of my topics.
I checked on wikipedia and found that: a laser pointer or laser pen is a small portable and visible laser designed to highlight something of interest by projecting a small bright spot of colored light onto it. I made a conclusion after reading these words: A pointer is no more than a battery-powered laser diode used for pointing. It is bright, visible and focusable (maybe and mostly). Of course, the most important is that it is laser.
Laser pointers today are quite different with the early ones. The early laser pointers were helium-neon (HeNe) gas lasers and generated laser radiation at 633 nm. They are designed to produce a laser beam with an output power no greater than 1 mw. And they are mostly red laser pointer. Today, besides the red laser pointer, other colors are possible too. And the 532 nm green laser is the most common alternative.
Sorted by the wavelength, a laser pointer has many types, such as red laser pointer, green laser pointer, blue laser pointer, violet purple laser pointer, yellow laser pointer, and so on.
A red laser pointer is of 650nm, while a green laser pointer is 532nm. Blue with 473nm, and violet blue with 405nm. The newest yellow is with 593.5nm, it is rarely seen and used. And it seems that the red-orange laser pointer is also available in technology. Though seldom of us can purchase and have one of them.
Sorted by the output power, there are 1mw laser pointer, 5mw laser pointer, 10mw laser, 50mw, 100mw, 150mw, 200mw, 250mw. According to the FDA, lasers are classified. Visible laser pointers operating at less than 1mW power are Class 2 or II and visible laser pointers operating with 15mW power are Class 3A or IIIa. Class 3B/IIIb lasers operating between 5500mW and Class 4/IV lasers operating above 500mW cannot be legally promoted as laser pointers.
A laser pointer is bright. If it isn't, it must be broken (hehe). The apparent brightness of a laser beam depends not only on the optical power of the laser and the reflectivity of the surface, but also on the chromatic 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 at low light levels in the green region of the spectrum. The redder and bluer wavelength decreases sensitivity.
Moreover, doctors say that laser pointers with power less than 5 mW are safe to use. The small width of the beam and low power of typical laser pointers make the beam itself invisible in a reasonably clean atmosphere, showing a point of light when striking an opaque surface. And we should better wear a pair of laser goggle to protect our eyes when playing with a high power laser pointer (more than 50mw).
Things emerge as the times require. The application of laser pointer is very widely. Laser pointers are often used in educational and business presentations. Visual demonstration is also in need of them. Laser pointers are usually used as an eye-catching pointing device.
Red laser pointers can be used in almost any indoor or low-light situation. It can make up for the inconvenience by pointing out details by hand, such as in construction work or interior decorating. Green laser pointers can be used for similar purposes as well as outdoors in daylight, even for longer distances.
A laser pointer is very useful. However, it can be evil when used not properly. I do hope that everyone around us can use them properly. Only in this way can our achievements be carried forward.
