Beam divergence angle is small, for practical applications is of great significance: first, the system can reduce the optical emission optical lenses or mirrors and other components of the aperture size; more importantly, the smaller the beam divergence, the energy in a more focused direction of polish , so you can shoot very far. Such as optical transmission system with ruby laser system, received thousands of kilometers of external beam inclination of only one cup size mouth is on the moon shine, but also 2 km spot size. Therefore, the use of the laser was the first time the Earth to the Moon's precise range. The general direction of the best light searchlight, assuming that the light intensity is large enough (actually less than), the spot diameter on the moon shine at least tens of thousands of kilometers, can cover the entire moon. As the laser direction, strength and high, so you can aim accurately, shoot too far. You may operate the green laster pointer at any corner of the place.Take advantage of this feature made laser rangefinder and laser radar, which measure the target distance, direction and speed than the average microwave radar to be much more accurate. Such as lunar laser ranging, 38? 40,000 km error of only 1 meter (the best record of 10 cm), very accurate. Precision laser radar can automatically track aircraft, missiles, satellites and other high-speed flight body, can be used to measure the distribution of clouds and atmospheric pollution detection. Short-range ground laser communications, confidentiality, particularly strong, can not easily be cut and interference by the enemy.You may operate the 100mW laser pointer at any corner of the certain room. In addition, the use of laser can be made highly directional laser-guided weapons, mission rate has improved. In building water conservancy projects, railways and roads, the need to dig long tunnels, you can use the laser to "guide", along the direction of laser construction, the tunnel will be played straight and accurate. (B) Huang Lvqing violet red-orange - color is good from the electromagnetic spectrum, we can see, there is a wavelength corresponding to a color. "Re-setting sun after the rain, rainbow frames the sky", which is our common natural phenomenon, because sunlight contains all the wavelengths of visible light, that is, all the world contains a variety of colors, the result is white. The 200mW Laser Pointer can be used combining with the projector.Therefore, the "white" light is red, orange, yellow, green, green, blue, purple colors of light mixed. An optical wavelength range included in the smaller, the more pure the color it looks more bright, usually we have called this the monochromatic high. Generally smaller than the wavelength range of a few angstroms (1 angstrom = 1 billionth of a centimeter) section of the radiation as monochromatic light source of monochromatic light emission as monochromatic light source. And laser beam divergence angle is a measure of the beam direction as a sign of good or bad, the line width is a measure of the merits of the standard color. People in long-term production and scientific experiments, has created a lot of monochromatic light sources, such as a variety of neon, mercury vapor lamps, sodium lamps and so on.10mW blue violet laser pointer is environment protected. The best previous monochromatic light source 86 is the isotope krypton lamp, which emitted light at low temperatures only the wavelength range of about 0? 005 angstroms, the line width at room temperature to 0? 0095 angstroms, so its color is very bright.The emergence of the laser, in monochromatic light caused a big leap.