itted light is monochromatic, meaning only one wavelength, and one directional. For a laser to work three components are needed. First a gain medium that can amplify light through it. Second an energy pump source to create a population inversion, (this is a condition when electrons in high energy levels are more numerous than electrons in lower energy levels), in the gain medium. Finally two mirrors that form a resonator cavity where small units of energy released from the atoms called photons move back and forth between the mirrors triggering more stimulated emissions. The energy of a photon is calculated using the equation:
             where E is the energy of a photon, h is Planck's constant (equal to 6.63 x 10-34) and v is the frequency. As the photons are moving back and forth between the mirrors an intense, directional, and monochromatic laser light seeps through one of the mirrors which is only partially silvered.
             Lasers are generally based on the medium used, and are classified as solid state, gas, semiconductor, or liquid. Solid state lasers have a solid gain medium in which atoms are excited. The first ever laser was a solid state laser with a ruby core and pumped buy a xenon flash tube. This laser was made by Theodore Maiman in 1960. The most common solid state lasers are constructed out of ruby crystal, neodymium-doped or yttrium-aluminum and coated with a highly reflecting nonmetallic film. These lasers have the highest power output and are usually operated in a pulsed manner to generate bursts of light over a short period of time. These short bursts are useful for studying ph
             ...