Lasers in a nutshell

When someone mentions "Laser" we are instantly reminded of a bright light beam whether it's from a James Bond movie or from a stage display. But what exactly is a Laser?

In plain English, it's only a light source. Just like an ordinary light bulb or sunlight, a laser emits light. So what's so special about a laser? Well, there are a couple of differences, the major one being the high degree of coherence (I'm not going to explain that now since it's going to be very technical) another is the high intensities they can produce.

In some instances Laser intensities can be so high that just by looking at an object illuminated by a laser can burn your eyes for good! So lasers are categorised according to the level of damage that they can cause. Therefore lasers categorised as class 3 and above require wearing goggles and protective clothing.

A description of the importance of lasers is beyond my scope, they range from medical applications such as cancer cell burning and teeth whitening to metal cutting, engraving, and precision measurements of incredibly small distances, (I'm talking in the nanometer range).

I'll write about my research later on, for the moment I'm using a He-Ne laser which is categorised as 3B, that means I have to wear goggles, which can be quite a pain, for it cuts out most of the light and I keep knocking on things in the lab like a blind bat!