Laser

Light Amplification by Stimulated Emission of Radiation. Not the lead underpants sort of radiation, it's normally visible or near-visible wavelengths of light. Lasers in print are used as a source of intense, coherent light for exposing film, printing plates or screen mesh emulsions, or in laser printers and some digital presses as a way of discharging static charge to create image areas on photoelectric drums.