Light Amplification By Stimulated Emission Of Radiation
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Light Amplification By Stimulated Emission Of Radiation

Its Tee again, a sharp 7 year old. "Come here Tee". Called Tee's mom. "Explain to me what is meant by monochromatic light, coherent light and LASER". Said Tee's mom. "Just excitation mom, just excitation". Said Tee.

Describe Tee's explanation.

The strings: S7P3A32 (Force - Push).

The math:
Pj Problem of Interest is of type force (push). When an electron absorbs energy it is excited and pushed to a higher energy level. When it gives up the energy, it is pushed back to its original energy level.

A monochromatic light is a light of a single wavelength.
Light of the same wavelength that travel in step (crests of light wave travel next to one another and troughs travel next to one another) is coherent light.

A LASER is the acronym for Light Amplification by Stimulated Emission of Radiation. It is a device that produces coherent light.
Consider figure 22.14:
When an electron of a normal atom absorbs a photon of energy, it is pushed to a higher energy level and the atom becomes excited. When the electron gives up the photon-energy, it returns to its energy level prior to the excitation and the atom returns to its normalcy. It does happen that if an already excited atom is hit by a photon of energy, the atom does not absorb the photon-energy. Instead it releases the photon-energy it had already absorbed priorily. Consequently, there exist two coherent photons in the space. If these two coherent photons hit two other excited atoms, there will be four coherent photons in the space. If these four coherent photons hit four other excited atoms, there will be eight coherent photons in the space. This process by which an arithmetic series of coherent photons result from the interactions of photon-energies (radiation) and excited atoms is called stimulated emission of radiation. The arithmetic progression of coherent photons is light amplification.

A laser consists of a tube containing substances (gases, liquid or solid) whose light properties will cause the desired light wavelength to be produced. A mirror is placed at one end of the tube for total reflection and a partial mirror is placed at the other end to allow some light through it. Both mirrors allow the photons traveling down the tube to bounce back and forth within the tube in order to maximize collisions of photons and excited atoms. As the beam is amplified in the tube, a tiny percentage of its coherent light passes through the partial mirror and is manifested as the laser beam.

Blessed are they that have not seen, and yet have believed. John 20:29