The US military defines a directed-energy weapon (DEW) as a “device that affects a target by focusing onto it a beam of electromagnetic energy or atomic particles.” The focus of the military’s efforts is on high-energy lasers (HELs) and high-power microwaves (HPMs). HELs include both pulsed and continuous-wave (CW) devices, and their emissions span a broad spectral range—from long-wave IR down to x rays or even gamma rays. HPM devices, by contrast, are pulsed RF beams, whose emission may extend up to the millimeter-wave or higher frequency.
DEWs recently existed only in science fiction, commonly seen in the Star Wars movies and in the Star Trek television series. Despite the excitement among developers and many billions of dollars in military funding over six decades, lasers and other directed-energy devices were not common operational weapons. Indeed, developers of traditional kinetic-energy weapons (KEWs)—guns, bombs, and missiles, for instance—have jokingly said that DEWs...
