While laser pens are useful and fun, users need to pay attention to safe use, to avoid improper use. While the dangers of firearms and explosives are obvious, the possibility that a low power laser can cause severe damage to vision is something that needs to be stressed. For high power lasers, there may be fire and other hazards as well. For every laser user, always pay attention to laser safety.
Monochromatic: Light emitted by ordinary light sources is different in frequency, so it contains various colors. Lasers emit the same frequency of each photon, so laser is the best monochromatic light source.
High brightness: Due to the strong emission capability of the laser and the high concentration of energy, the brightness is very high, it is hundreds of times more than ordinary light, tens of billions of times higher than the brightness of the sun's surface. Brightness is an important indicator of the quality of a light source, if the medium intensity of the laser beam through the convergence, can produce a few thousand to tens of thousands of degrees in the focus of the high temperature.
Good directivity: the divergence angle of the laser beam is very small, almost a parallel light. The spot formed by the laser irradiation on the moon is only about 1 kilometers in diameter.
Coherence: coherence is common to all waves, but because of the quality of various light waves, resulting in their coherence is also high and low points. Ordinary light is spontaneous radiation, will not produce interference. Laser is different from the ordinary light source, it is stimulated radiation, with a strong coherence, so called coherent light.
Laser can bring good use, the use of the wrong way will bring some damage. With the laser pen caused by more and more accidents, the safe use of laser pen problem caused by more and more people concerned. For the laser pen, the biggest and most common injury is the human eye. Except for very low powered lasers, lasers do pose a hazard particularly to vision. But the high power laser will cause serious damage to the human eye, don't take your eyes for granted because once your eyes are damaged, they will not grow back!
So, when using a powerful laser pen, pay attention to wear a laser goggles to protect your eyes. At the same time, you have to do the following: