Lasers: What Everyone Should Know Essay

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Lasers: What Everyone Should Know

Lasers are very important tools in modern science, industry, and everyday life. From their creation over forty years ago their designs have improved and their usefulness increased. They work on physical principles that are a mix of both classical and quantum mechanical, thus making them great examples for demonstrating the properties of light and excited states of atoms and molecules. The process of producing laser light can be complicated, but the explanation of laser action, becomes easily accessible when an explanation of the underlying physical principles, and the apparatus involved in creating it is given. Indeed, there are a number of different types of lasers, solid-state lasers, gas
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Essentially, this is the name given to a device producing light that meets three qualifications. The first is that the light produced is completely in phase, meaning all crests and troughs in the waves line up perfectly, leading to only constructive interference. Next, all of the light produced is propagating in the exact same direction and not spreading out. Finally, all of the light is all the same color, and thus the same frequency. This indicates that all of the light is of the same energy, since the energy of light is proportional to its frequency. These devices are able to achieve such remarkable properties through a physical process known as stimulated emission of radiation, the basis for their name [1].

Before delving into the inner workings of a laser system, a little history is appropriate to better understand what events and discoveries led up to the development of these remarkable tools. In 1900 the first stride towards laser development came with the theory by Max Planck of the quantization of light energy into discrete packets which came to be known as photons, and the famous equation E = hv, where E is the energy of the photon, v is its frequency, and h is known as Planck’s constant. However, the first real foray into an idea that would directly lead to the development of lasers was the postulation by S.N. Bose, that photons will tend to travel together, and that the more of them there are the more likely they are to be found together.
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