A laser largely used in industry in which the primary lasing medium is carbon dioxide.

Most laser welding is done with a shield of inert gas flowing over the work surface to prevent plasma oxidation and absorption, to blow away debris, and to control heat reaction. The gas jet has the same axis as the beam so the two can be aimed together.

Also Coherent Radiation. Radiation composed of wave trains vibrating in phase with each other. Simply expressed: parallel rays of light.

Also Coherent Light.  Radiation composed of wave trains vibrating in phase with each other. Simply expressed: parallel rays of light.

Divergent light rays rendered parallel by means of a lens or other device, allowing a sharp image of the object to be focused at the focal plane of the lens.