Nations around the world are rapidly developing high-energy laser weapons for military missions on land and sea, and in the air and space. Visions of swarms of small, inexpensive drones filling the skies or skimming across the waves are motivating militaries to develop and deploy laser weapons as an alternative to costly and potentially overwhelmed missile-based defenses.
Laser weapons have been a staple of science fiction since long before lasers were even invented. More recently, they have also featured prominently in some conspiracy theories. Both types of fiction highlight the need to understand how laser weapons actually work and what they are used for.
How lasers work
A laser uses electricity to generate photons, or light particles. The photons pass through a gain medium, a material that creates a cascade of additional photons, which rapidly increases the number of photons. All these photons are then focused into a narrow beam by a beam director.
In the decades since the first laser was unveiled in 1960, engineers have developed a variety of lasers that generate photons at different wavelengths in the electromagnetic spectrum, from infrared to ultraviolet. The high-energy laser systems that are finding military applications are based on solid-state lasers that use special crystals to convert the input electrical energy into photons. A key aspect of high-power solid-state lasers is that the photons are created in the infrared…
