Part 1 of Essay
We have all at some point in our lives used or seen someone use a laser. They are used in compact disc players for stereos or computers, laser surgery, laser printers, holography, cutting and borring metals, communication, bar-code scanners, etc. Over the past three decades' lasers have become a tool used daily by many pe ....

Part 2 of Essay
.... is stimulated, as it falls back to a lower energy state, to emit a second photon of the same frequency, in phase with and in the same direction as the bombarding photon. This process is called stimulated emission. The bombarding photon of the emitted photon may then strike other excited atoms, stimulating further emission of photons, all of the same frequency and phase. This process produces a sudden burst of coherent radiation as all the atoms discharge in a rapid chain reaction. The light beam produces is usu ....