The laser — it’s so valuable to so many things we do. The Air Force has an entire lab devoted to researching and innovating with this powerful light. The lasers are all around us;
we can find them everywhere. In the military we use them for such things as targeting and simple things as laser pointers. In everyday life they’re at supermarkets in bar-code scanners. In CD and DVD players we use them to read the material on the surfaces of CDs. There are laser rulers and levels and Printers. Lasers send telephone and TV signals,
cut through metal, and even help doctors do surgery. A laser beam is a very coherent concentrated beam of light. Visible light, as we know it, is 400 to 700 nanometers. When you turn on a room switch the light fills the room. Coherent concentrated light is a single beam of light very concentrated — all the same wavelength. Visible light waves fan out, but in lasers all the light waves are parallel and move in a straight line. To see how lasers work let’s start with atoms. So we take atoms and atoms are composed of electrons protons and neutrons. When we excite those electrons and then they come back down in energy levels, they release photons which are light in a laser. We collect those photons and we bounce them back and forth between mirrors. We get them in a basically straight line –
you can think of it as like a marching band. We release them in a beam and that’s the directed energy or the laser beam. It’s a lot of fun because you get to touch things, put your hands on things, and do things that not very many people get a chance to do. That’s really pretty cool when you think about it.