Lasers are one of the most important enabling technologies developed over the past 50 years, and its impact is difficult to assess. Lasers are not only the engines of the modern information economy, enabling the rapid transmission of data and cost-effective storage over the Internet, but also an essential research tool without which science, technology and modern medicine would not progress. Laser pointers are usually used in reports, teaching, and tour guides. Staff will use it to project a light spot or a light to point to an object, but it is not suitable for use in certain places, such as art galleries (some paintings are afraid of light), zoos, etc. Using a green laser pointer may cause serious damage to the retina and even blindness, so children should not use it.
The difference in power will determine the brightness of a particular laser, keeping in mind the color of the beam. For a laser that can light a match or pop a balloon, you need at least 200mW of any color, and the higher the power, the greater the ability to burn and the greater the range of the laser. A 200mW green laser can be seen more than 10 miles straight from the site. Some lasers can emit multiple monochromatic frequencies at the same time, but not a continuous spectrum containing all visible light colors, you can make light bulbs.
Since photons also have momentum, atoms or molecules moving in the opposite direction to the laser beam can be broken down by the high power laser pointer, reducing the speed of the atoms/molecules. You can think of it as two billiard balls touching each other and decelerating each other due to momentum transfer. The atom then emits a photon after absorbing this incoming photon. Lasers can be made with nearly non-divergent beams, so their reflections from the mirrors Apollo 11 placed on the moon could be measured on Earth, or they could be made to uniformly illuminate large areas for manufacturing applications.
