Directed-Energy Weapons - Laser, Directed-Energy Weapon, Microwave Burn, Raygun, Active Denial System, Sonic Weapon, Particle Beam Weapon (Paperback)

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 35. Chapters: Laser, Directed-energy weapon, Microwave burn, Raygun, Active Denial System, Sonic weapon, Particle beam weapon, LED Incapacitator, Vigilant Eagle, ZEUS-HLONS, Electrolaser, Solar-pumped laser, Shiva Star, MIRACL, ZM-87, Boeing Laser Avenger, Veiling-glare laser, MEDUSA, StunStrike. Excerpt: A laser is a device that emits light (electromagnetic radiation) through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation. The emitted laser light is notable for its high degree of spatial and temporal coherence, unattainable using other technologies. Spatial coherence typically is expressed through the output being a narrow beam which is diffraction-limited, often a so-called "pencil beam." Laser beams can be focused to very tiny spots, achieving a very high irradiance. Or they can be launched into a beam of very low divergence in order to concentrate their power at a large distance. Temporal (or longitudinal) coherence implies a polarized wave at a single frequency whose phase is correlated over a relatively large distance (the coherence length) along the beam. A beam produced by a thermal or other incoherent light source has an instantaneous amplitude and phase which vary randomly with respect to time and position, and thus a very short coherence length. Most so-called "single wavelength" lasers actually produce radiation in several modes having slightly different frequencies (wavelengths), often not in a single polarization. And although temporal coherence implies monochromaticity, there are even lasers that emit a broad spectrum of light, or emit different wavelengths of light simultaneously. There are some lasers which are not single spatial mode and consequently their light beams diverge mor...