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what is the difference between a laser beam and a normal light wave ? Why don't laser beams spread out like light waves?
As chiralSPO's answer said, lasers are coherent, which is a requirement for them to not spread out.
spotlights and other light sources that go somewhat in a nice beam
Quote from: JPAs chiralSPO's answer said, lasers are coherent, which is a requirement for them to not spread out. Actually that's not what chiralSPO said, exactly. He said that laser light spreads out much more slowly. By the time that the beam gets to, say, the moon, it's spread ot by miles, perhaps by hundreds of miles even.
Maybe laser is standing wave and light is random wave?
You can make laser light spread out, or focus it, just as with any other light. It just happens to be easier to control and less prone to dispersion because it has a very narrow bandwidth and a long coherence length. In most cases it is generated inherently almost parallel, unlike other light sources which are inherently radial in nature, but neither statement is absolute.
Maybe laser is standing wave?
broad spectrum light to come from extremely short laser pulses