A HEL focuses optical power on one point and heats or burns the target: drones, missiles, optics and sensors. Its strengths are speed-of-light effect, pinpoint precision, a low cost per shot and a deep magazine. But the limitations are substantial:
- Line of sight required: a laser does not bend over the horizon (Radar) and does not go through mountains or buildings.
- Dwell time: the target has to be "held" for several seconds to deliver enough energy — difficult against fast, manoeuvring targets.
- Atmosphere: absorption and scattering weaken the beam, and thermal blooming (the beam heats the air and defocuses) comes into play. Rain, fog and dust make this worse — compare the atmospheric windows for IR (Infrared).
Examples in development or service include naval systems such as the American HELIOS, the Israeli Iron Beam and the British DragonFire.