Super discount laser pointer first come first serve

In the classification system,.300MW green laser net sales, although some labeled as minority, but did not say specific use reporter noticed, some laser pen sales are who? Class 1 product laser said 3A ", is a class 1 laser, some products belong to the "class" or "3B" class, but also very few, there are "4B". According to GB7247 laser safety standard radiation protection requirements, class 1 2, laser 3A low, laser 3B, high power laser 4. The principle behind lasers is stimulated radiation, which is actually quite simple and was first proposed by Albert Einstein in 1916. But it took 44 years to build a stable laser. Laser has three main elements: working matter, pumping source (or excitation source), resonator. These three strange names may seem daunting at first sight, but they are only paper tigers. Let me tell you more slowly. "Working matter" is something that emits light, the equivalent of a filament (rubies for the first laser); A pump source, simply known as a power source, continuously pumps electrons from a lower energy state to a higher energy state through a current.