Greetings, my name is Kevin. Ever wonder how a laser works? Well, this short essay here is for you then! I will be posting several 'papers', if you will, about science to all who are interested. ---- First, lasers. Laser is actually an acronym for L.A.S.E.R, or "Light ampified by stimulated eletro-magnetic radiation." Now, this may sound tough to swallow, but let me explain it another way: Light is composed of several different frequences. There are very high frequences, and very low freqences. These frequences act like waves, (and particles, but more on that later) which travel over distance. Light can also be called Eletromagnetic Radiation. Ah ha! So that's what that means. Like I said, light is composed out of several different frequences and wavelengths. So when you see a rainbow, it is actually the entire spectrum of light. A prism seperates the light into its corresponding frequences and wavelengths. At any rate, now that we know this information, we can move onto lasers. A laser has the following properties: 1) It is coherant. 2) It it concentrated. 3) It has successive 'steps'. Coherant means that is comprised of a single wavelength. (Instead of light that is in every spectrum, laser is only a small portion of all spectrums of light) There are 2 or more types of lasers. 2 that I can think of right now are: 1) Semi-conductor lasers. (Uses chips to produce LED light) 2) Gas lasers. (Very strong) Semi-conductor lasers are the pen pointer lasers, and the light is red. Gas lasers can be powerful enough to melt though things. (Like the stuff you see in the movies!) Part II) Componets. We will now cover the componets of a gas laser. It can be seperated in the following parts: 1) Flourescent glass tube with tungsten filament. 2) Lasing medium filled with gas. (Fig 1.0) __________________________ |_________________________ | <-- (This is the flourescent glass tube with tungsten filament. Similiar to the "Open" signs you see in restaurants.) (Fig 1.1) |----------------------| | | <-- (This is called the lasing me- |----------------------| -dium.) And finally, this is how a basic gas laser works: Step 1) The flourescent light goes on. The light is directed downward. Step 2) The light stimulates the atoms in the lasing medium (and there is gas within this chamber). Each atom goes from ground state, to a higher exited energy level. Then, the atom(s) go back to their orginal ground level. In the process, they emit a photon. Step 3) A photon is a particle of light. Together, billions of photons create the visible spectrum of light we all see today. However, the laser light that comes out is only a single part of the total spectrum of light. Step 4) On the left side of the lasing medium, there is a reflective mirror. On the right side, there is a reflective mirror but half silvered. The photons travel to the left mirror, bounce off and go to the right, and the photons that make it out, together, make laser light that you see. --- Note: For all of you brainiacts out there, please do not humilate me. I'm 16 years old, and I just want to help spread knowledge to people who want to know more about lasers. I'm sure something similiar has been constructed like this before, but I really want to help and it sums it up nicely. I am dsylexic, so if you see any errors please let me know via Private Message.