How to make laser pen plane beam?

Lasers are used for a variety of purposes, including pointing out objects during demonstrations, alighting materials on construction sites and in homes, and for doctors performing cosmetic and surgical procedures. Lasers are used in many of the objects you encounter every day, including CD and DVD players, bar code scanners, dental drills, laser-guided tools such as a level, and laser Pointers. Some lasers emit radiation in the form of light. Others emit invisible radiation, such as ultraviolet or infrared radiation. In general, laser radiation is harmless in itself and behaves very much like ordinary light in its interactions with the body. Laser radiation should not be confused with radio waves, microwaves, ionizing X-rays, or radiation from radioactive substances such as radium.