Excitation wavelength of 808nm infrared laser nonlinear crystal to generate 1064nm infrared light, and then the frequency doubling 532nm green, is a solid laser. Some green lasers pointers operate in pulse or quasi-continuous mode down to reduce cooling problems and prolong battery life. Announced undesired harmonic green laser light has a higher efficiency. Even at night, low-power green Rayleigh scattering due to atmospheric molecules can also see that this laser pointer is often used for astronomy lovers pointing stars and constellations. Green Laser Pointer can have a variety of output power. 5mW to use the safest, and can also be found in dark lighting, so no need for the guidance of the purpose of a stronger power.
In addition to safety, the use of laser pens must be careful. In the galleries, because part of the paintings may photophobia, not suitable for use laser pointer. In the zoo, to avoid frightened animals should not be used a laser pointer. Amateur astronomers in the use of laser pointer refers to the star, it should be noted that frequent and prolonged use should not refer to star pens, not to hinder others stargazing and photography. In crowded public places, in order to avoid accidental injury to others, you should stop using the laser pointer. Some high power laser pointer will be significant thermal effect, can not long continuous use, especially for temperature sensitive solid-state laser.