How Do Lasers Work?
Almost all of us are acquainted with lasers, as we have used or seen lasers in action at some point of our lives. Lasers are used in a variety of places, like for pointers for a presentation in a corporate boardroom classroom or as a cat toy.
A closer example at home is the usage of lasers in the CD players, where a laser is used to read the information stored in the CD. A recent breakthrough in this field is BLU ray discs, in which a high intensity laser is used to read ultra high capacity discs.
Lasers also find intensive application in fields such as holography (holography is the art of etching a three-dimensional image onto a material using lasers – the type of laser depends upon the material to be etched). Apart from this, lasers are used by the military in many of their programs, to correct eye disorders by LASIK surgeries, and in industries that use dangerous chemicals to detect leakage.
So that’s what they’re used for, but we haven’t answered the question of what a laser actually is. LASER is an acronym that stands for Light Amplification by Stimulated Emission of Radiation. Now what this means is that lasers are basically tiny particles which are radiated, and these particles are converted to laser beams by manipulating them by a number of means.
Unlike white light which is made up of seven colors – ROY G BIV, or red, orange, yellow, green, blue, indigo, and violet, the seven colors which form the rainbow, lasers are usually made up of monochromatic (single-colored) light. This is because white light spreads out as it travels, but monochromatic light is almost non divergent, that is it does not spread much even after traveling large distances.
This increases the range of the laser light. Moreover, normal white light will refract (bend) differently when it hits an object – each color bends at a slightly different angle. Monochromatic light only has to bend in one way, so it keeps its coherence (the ability of light rays to stay together as a bundle), so the laser stays more focused.
Monochromatic light can be generated by utilizing free electrons (electrons are very small parts of atoms which are the building blocks of all kinds of matter existing in the universe). Electrons, when highly energized, give out that energy in the form of radiation before coming back to their normal state. 
Specific types of radiation can be created by electrons energized to specific energy levels, giving out single colored light. This light is then focused into a single powerful beam by one of several methods, such as by using a cathode tube or by utilizing ionized air in vacuum tubes.
The following is a list of the types of lasers and their applications, and shows that lasers can be produced by different methods:
*Dye Lasers- used for spectroscopy, various kinds of research, birthmark removal, and for separating isotopes. The range of this laser can be tuned by changing the kind of dye used.
*Free electron lasers- has various medical uses, and is used in atmospheric research and material science.
*Nickel-like samarium lasers- can be used for high resolution microscopy and holography.
*Raman lasers- used in creating optical signal amplification for telecommunications.
*Nuclear pumped lasers- currently being used for research.
Lasers, if used in the right way have innumerous applications, which are growing by the day, but they can also be devastating if used in the wrong way. Of course, always be careful when using, playing with or looking at lazers (such as when you play with a lazer cat toy), they can be very damaging to your eyes (or your kitty’s) if you look directly at them.
July 22nd, 2008 at 9:35 am
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