Do you know laser light?

Yesterday i saw a film about the laser light. It made me feel amazing and i’m interested in it. I want to know what is a laser? How are laser pointers classified and what makes a laser light different from other kinds of light?

Over the last few years laser light has aroused some public concern. As a consumer product, laser pointers are designed to be safe when used for their intended purpose. Unfortunately, however, the laser pointer can easily be misused.

Laser pointers are helpful tools but they must be used responsibly. Common sense dictates that users should never direct a laser pointer beam at another person. And lasers with power over 5 mW should not be used as pointers.

Lasers have many important applications. They are used in common consumer devices such as DVD players, laser printers, andbarcode scanners. A green laser has more versatility, strength, and brightness than traditional red laser light. This color of laser can be produced in a small, handheld tool that looks like a miniature flashlight. Amateur astronomers often use a green laser because it reaches so far into the atmosphere, with a visible beam, that you can point out stars and galaxies.

Lasers are distinguished from other light sources by their coherence. Spatial coherence is typically expressed through the output being a narrow beam which is diffraction-limited, often a so-called "pencil beam." Laser beams can be focused to very tiny spots, achieving a very high irradiance, or they can be launched into beams of very low divergence in order to concentrate their power at a large distance.

The following are product info about red laser pointer:

New Style Laser Pen Features:
1.Powerful New Style laser pen,red beam laser pen
2.The red beam itself can be seen in mid-air in dark conditions, which allows the red laser pointer to be used for pointing to star constellations
3.Apply to: Camping, hiking, signaling, tour guides, bird watching, professional presentations, astronomers pointing out constellations and stars in the night sky
4.Solid, heavy duty construction
5.Small & compact size, convenient to carry
Just press the button of the pen, following the green laser light
6.Color: Black as shown in the picture

New Style Laser Pen Specifications:
1.Output wavelength:532 nm
2.The output power:1-200MW
3.Control circuit:APC line
4.Working voltage：DC=3V
5.Working current：I<450mA
6.Operating temperature:+20℃～＋30℃
7.Storage temperature:+10℃～＋40℃

New Style Laser Pen Packing list:
1 x red Light Laser Pen