In Military applications within the EMS and Infrared we kept running into the same gap: passive EO/IR sensors see razor-sharp where something is, but not how far away. The laser closes that gap — and does much more along the way: marking targets for precision weapons, measuring distances to the centimetre, communicating over beams that are almost impossible to intercept, and blinding sensors.
LASER stands for Light Amplification by Stimulated Emission of Radiation. It is not a separate part of the spectrum but a way of generating light: most military lasers operate in the near infrared (1.06 µm and 1.55 µm) — invisible to the eye, good at passing through the atmosphere, and dangerously concentrated.
This chapter first covers what makes laser light physically special, then the difference between continuous and pulsed applications, and ends with the two most important military laser systems: the rangefinder and the designator.