a directed energy beam system uses an ultra - fast laser system , such as one using a titanium - sapphire infrared laser to produce a thin ionizing beam through the atmosphere . the beam is moved in either a circular or rectangular fashion to produce a conductive shell to act as a waveguide for microwave energy . because the waveguide is produced by a plasma it is called a plasma beam waveguide . the directed energy beam system can be used as a weapon , to provide power to an unmanned aerial vehicle such as for providing communications in a cellular telephone system , or as an ultra - precise radar system .