What are directed energy weapons (DEWs) and how do they work?

Directed energy weapons (DEWs) are systems that convert electrical or chemical energy into focused electromagnetic radiation and direct it toward a target, with the purpose of degrading, neutralising or destroying that target without the need of firing traditional projectiles. According to US Navy's Office of Naval Research, these weapons include high-energy lasers (HEL) and high-power microwaves (HPM). Other types also include Millimeter Waves and Particle beam weapons.

Unlike conventional weapons that rely on explosive force or kinetic impact, DEWs deliver energy at the speed of light across the electromagnetic spectrum. When that energy is further concentrated on a specific point or system, it can produce effects ranging from temporary disruption of electronics to physical damage of materials. These are electromagnetic waves used to disrupt or damage systems like radars or communication equipment. The measure of a the directed energy weapon’s effectiveness lies in its ability to focus energy reliably at range with precision and controllable effect.

There are several technologies that come under DEWs. High-energy lasers, that emit photons as concentrated beams of light have the ability to cut or burn through materials. High-power microwaves can produce broad electromagnetic fields that directly interact with electronics, potentially disabling systems without any physical contact. Millimeter waves are electromagnetic waves used to disrupt or damage systems like radars or communication equipment, and Particle beam weapons have the ability to accelerate charged particles to high velocities and direct them at a target, causing physical damage or radiation damage. Especially HEL and HPM are being explored by militaries across the world to address emerging threats such as swarming drones or missile defence.

Laser based Directed Energy Weapon system is one of the most important force multiplier in modern day warfare specifically to counter new asymmetric and disruptive threats like Drones and Unmanned Aerial Vehicles (UAVs), incoming missiles and even enemy radar systems.

Laser beams can scatter and lose focus when passing through atmospheric turbulence, particularly over long distances or in maritime environments. Weapon systems including Iron Beam, HELIOS, DragonFire and India's MK-II (A) are some of the examples of DEWs.

Because DEWs require only energy, not munitions, once installed they can deliver deep magazines and rapid, repeatable use. Precise targeting can reduce collateral damage, and directed energy systems can operate without the logistics of ammunition supply. Their ability to engage threats nearly instantaneously further offers distinct tactical advantages in modern theatres of operations.