A load of atoms (a solid, liquid, or gas) with electrons in them that we can stimulate.

Photons (light particles) all at once so they line up to form a really concentrated light beam. If you're not sure how this happens, take a look at the boxĪ laser is effectively a machine that makes billions of atoms pump out trillions of

These three things make lasers precise, powerful, and amazingly useful beams of energy.īefore you can understand how a laser works, you need to know how an Parade of soldiers all marching precisely in step. Platform of a railroad station by comparison, a laser beam is like a Of commuters, pushing and shoving, jostling their way down the

Light are exactly in step: the crest of every wave is lined up with Of some beams mixed with the troughs of others), the waves in laser Where the light waves in a flashlight beam are all jumbled up (with the crests.There's a third important difference you won't have noticed: Longer distance (we say it's highly collimated). Where a flashlight beam spreads out through a lens into a short and fairlyįuzzy cone, a laser shoots a much tighter, narrower beam over a much.Invisible 'color' such as infrared or ultraviolet). Precise frequency and color-often bright red or green or an Makes what's called monochromatic light (of a single, very Where a flashlight produces 'white' light (a mixture of all differentĬolors, made by light waves of all different frequencies), a laser.Two very important differences straightaway: If you've even seen a laser in a science lab, you'll have noticed (Department of Energy/National Renewable Energy Laboratory). Picture by Warren Gretz courtesy of US DOE/NREL Photo: It's much easier to make laser beams follow precise paths than ordinary light beams,Īs in this experiment to develop better solar cells. It starts off with weak light and keeps adding more and more energy so the light waves become ever more concentrated. Imagine doing this a few million times in the open ocean.īefore long, you'd have mountainous waves towering over your head! A laser does something similar with light waves. If you keep moving your hands in step with the waves you make, the The bathtub you can make quite strong waves. You've probably noticed that if you move your hands back and forth in Ripples in your bathtub and huge waves on the sea. The difference between ordinary light and laser light is like the difference between Lasers are more than just powerful flashlights. Photo by Greg Vojtko courtesy of US Navy and Using laser beams, carried out at the US Navy's Naval Surface Warfare Center (NSWC). Photo: A scientific experiment to check the alignment of optical equipment But how does this happen, exactly? What's going on inside a laser? Let's take a closer look! It's a tube that concentrates light over and over again until itĮmerges in a really powerful beam. Understand what they are or how they work? Not, all of us use lasers all day long, but how many of us really That lasers fire down fiber-optic cables.

Them, and we send and receive emails over the Internet with signals Our clothes are cut with lasers, we fix our eyesight with Laser printers), and in the stores where we shop (inīarcode scanners). Today, we all have lasers in our homes (in CD and DVD players), in our offices (in But apart from Bond villains, no-oneĮlse had any idea what to do with lasers famously, they were described as 'a solution looking for a problem.' James Bond, was almost chopped in half by a laser beam in the 1964įilm Goldfinger. Thrilling examples of cutting-edge science: secret agent 007, Last updated: September 9, 2023.Įnough to zoom miles into the sky or cut through lumps of metal.Īlthough they seem pretty recent inventions, they've actuallyīeen with us over half a century: the theory was figured out in 1958 the first

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