If you wish to technically broach the concept of LASER, the first thing you should probably learn is that LASER is an acronym and it expands to Light Amplification by Stimulated Emission of Radiation. But to a layman, a LASER device is just another light source with a special property. It can be channelized into a single straight line and is visible from a longer distance while normal light sources just fade away into convex beams.
Now, as the book “LASER: Light of a million uses” rightly points out, the uses of a LASER light source are plenty, but what are you buying it for? You might have seen professors dangling a pen during presentations and using it to point at screens. Well, that’s the simplest form of a LASER light and it is commonly used as a pointing device at slide shows and presentations. It doesn’t matter if you use red LASER or green LASER as long as it serves the purpose. With the rate of pollution due to fireworks, it would be nice to have a LASER light display instead of smoke and fire all across the sky on the fourth of July or Guy Fawkes’ Day. If you’re a pyromaniac, you may even choose to use LASER to ignite stuff like paper, cardboard boxes, cotton and matches. Use your creativity to even light a cigarette or a fat Cuban cigar if you are a smoker.
In glass cutting industries, they are used for cutting glass with an impressive amount of precision and accuracy. This has recently been extrapolated to many other industries. If you’re in construction, this can be used to even measure distances and depths of structures. Its practical application in science extends to the fields of biology, spectroscopy and chemistry. A regular camper might consider the use of LASER beams to scare away wild animals. Unless you’re a soldier, you would not be carrying a high power LASER beam generator of more than 1W power because it becomes a potential weapon. Battlefields usually have a lot to do with LASER where they are used as weapons and beacons.
While you don’t have to be a scientist, a little bit of scientific knowledge would help you understand how LASER is generated. The expansion of the term gives a very succinct description of how a LASER beam is created. Let’s take you back to the basics of matter; as you know, all matter is made of molecules which in turn are composed of tiny particles called atoms. An atom has a central nucleus made of protons and neutrons; small negatively charged particles called electrons circulate the nucleus in a way similar to that of the sun and the planets in the solar system. This is just a depiction of the balanced state of an atom. Consider that the atom is heated or given a bit of energy in some form – this causes the electrons in its orbit to go to an excited state resulting in the formation of an excited atom. If you extrapolate this concept to an object which contains millions of atoms, you have myriad atoms in their excited state. But how is the beam of red light generated? The answer is simple – the tendency of atoms to go back to their balanced state results in the creation of a light energy packet called a photon. It’s something like this – somebody gives you money, you become extremely excited and then you decide that you were better off when you didn’t have any money and throw it into a lake, except that there are a million other people like you dumping all their money in a lake. This way, when all the photons come together and travel in a single direction, it forms a LASER beam.