Part 1 of Essay
Before we can learn about we need to know a little bit about light (since that is what a laser is made of). Light from our sun, or from an electric bulb, is called white light. It is really a mixture of all the different colours of light. The colours range from violet, indigo, and blue, to green, yellow, orange, and red. ....

Part 2 of Essay
.... in which the wavelengths of the light are all the same length, and the crests of these waves are all lined up, or in PHASE. The word Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. What does that mean? Basically a laser is a device which produces and then amplifies light waves and concentrates them into an intense penetrating beam. The principles of the laser (and it's cousin the maser) were established long before these devices were successfully developed. In 1916 Albert Ei ....