The early Laser pointer (HeNe) HeNe gas laser produced a laser with a wavelength of 633nm, usually 1mW. The cheapest laser pointer uses a deep red laser diode with a wavelength close to 670/650nm. The more expensive diodes use red and orange 635nm diodes. Other colors are also possible, and the 532 nm green laser is the most common choice. Later, an orange-yellow laser pointer appeared with a wavelength of 593.5 nm. The 473nm blue laser pointer came out in 2005 and came out in September. In early 2010, a blue-violet laser pointer with a wavelength of 405 nm appeared.
The brightness of the spot from the laser beam depends on the laser power and the reflectivity of the surface. At the same power, the human eye is most sensitive in the green region of the spectrum (wavelength 520-570nm), which appears to be brighter than other colors. The sensitivity of red or blue wavelengths is reduced.
laser engraver, usually represents milliwatt (mW) output power. Lasers in the United States are classified by the American National Standards Institute and the Food and Drug Administration (FDA). The power of the visible laser pointer (400-700nm) is lower than 1mW, level 2 or II, and the visible laser pointer 1-5mW, level 3A or IIIa. Class 3B or IIIb lasers produce 5 to 500mW; Class 4 or Class 4 lasers produce power exceeding 500mW. US FDA federal regulations stipulate that "demonstration laser products" must meet applicable requirements, such as Class I, IIA or IIIA equipment.
Laser pointers are often used as eye-catching points in education, business presentations and visual presentations. The red laser pointer can be used in almost any indoor or low light conditions, and pointed out that the details on the manual may cause inconvenience, such as construction work or interior decoration. The green blue laser pointer can be used for similar purposes, as well as outdoor use in direct sunlight or greater distances.
The laser pointer has a wide range of applications. The green laser pointer can also be used by astronomy enthusiasts. The green laser pointer beam can usually be clearly seen on a moonless night and can accurately point out the vicinity of a single star to others. In addition, these commonly used green laser pointers were given lectures on astronomy by astronomers. Astronomical laser pointers are also usually used for specific stars or specific locations, so the telescope can be mounted on the telescope. Laser alignment is easier than using eyepiece alignment.