A Laser Pointer is a light pen, especially useful for projected presentations. The laser pointer form is conveniently sized, remote control keys, ballpoint pens, or used in combination with remote control (demonstrator). The first laser Pointers only emitted red light, but greens such as blue, yellow and orange appeared on the market. This light is produced by a special laser diode. A lens mounted in front of it turns the beam into a beam of light. Its lighting intensity and the maximum distance it can bridge depend on the light output of the laser diode. Power is measured in milliwatts (mW). Laser Pointers are divided into different categories for easy identification. Grades range from 1 to 4. Class 1 laser has the lowest luminosity, while class 4 laser has the highest intensity. This classification indicates whether the beam from the laser pointer is dangerous or harmless when it hits the eye.
Class I and CLASS II lasers can be used for serious lectures and do not damage under short periods of light. However, staring into your eyes for a long time or using a magnifying glass can be harmful to your health. Before laser diodes were available at low cost, so-called light indicators consisting of modified flashlights were the first. The lamp does not use curved mirrors, but is equipped with optical lenses that allow simple projectors to project arrow symbols (such as planes or contours). The advantage of this arrangement is that the arrow symbols can point to something more meaningful than a laser pointer.