1. Light Amplification by Stimulated Emission of Radiation By: James Vanderburg & J.P. Brown

2. An atom is the smallest component of an element, having the same properties as that element, consisting of a nucleus and electrons. A nucleus contains neutrons and protons, and at least one electron which is bound to the nucleus by electromagnetic force.

3. An electron is a subatomic particle that has a negative charge. The electrons have a wave-like behavior when bound to the nucleus which is all part of the atomic orbital. Electrons can exist at different energy levels. Electrons can fall from a higher energy level to a lower energy level. This process emits light because of the energy reduction within the orbital.

4. Population inversion occurs when a system exists in state with more members in an excited state than a lower state. This is important for lasers because it is necessary for a standard laser to work. The laser needs more atoms in an excited state than a lower energy state. A laser needs continuous electrons transitioning to a lower energy state to function. The transitioning allows the light to be emitted.

6. The light that is emitted from the laser is monochromatic and coherent. Monochromatic means that it contains one specific wavelength of light. Coherent means that the light moves in step with the others. The light launches in unison unlike a flashlight, which releases light in many directions and the light cannot be pinpointed.

7. Solid-State Lasers: has lasing material distributed in a solid matrix, such as a ruby or neodymium: yttrium-aluminum garnet “Yag” laser. The neodymium-Yag laser emits infrared light. Gas Lasers: helium and helium-neon are the most common and output a visible red light. These lasers are usually used for cutting hard material. Excimer Lasers: uses a variety of reactive gases that when electrically stimulated, a pseudo molecule (dimer) is produced. When lased, the dimer makes ultraviolet light. Dye Lasers: use organic dyes in liquid or suspension and are tunable over a broad range of wavelengths. Semiconductor Lasers (Diode Lasers): not solid-state lasers, and are usually very small and low powered. May be used in larger arrays, such as laser printers or CD players.

8. "coherent." Collins English Dictionary - Complete & Unabridged 10th Edition. HarperCollins Publishers. 03 Aug. 2011.. http://dictionary.reference.com/browse/coherent "coherent." Collins English Dictionary - Complete & Unabridged 10th Edition. HarperCollins Publishers. 03 Aug. 2011.. http://dictionary.reference.com/browse/coherent Paul, D.J. "Population Inversion." University of Cambridge. N.p., 2006. Web. 3 Aug 2011..