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How Does a Laser Work? Quantum Nature of Light - [3]

More Lessons: http://www.MathAndScience.com Twitter:   / jasongibsonmath   In this lesson, you will learn how lasers work. We begin that laser stands for light amplification by stimulated emission of radiation. We discuss how stimulated emission of photons differ from spontaneous emission of photons. Next, we discuss the energy levels that electrons occupy in the region surrounding the atom, and outline how we can calculate the energy of released photons when an electron decays from a higher energy to a lower energy state using plank's relation for the energy of a photon. Next, we discuss that in order to make a laser, we need a population inversion of electrons in a higher metastable state, that then decay into a lower state when a photon stimulates the emission of a new photon in the lasing medium. Finally, we discuss how to construct an optical resonant cavity, where the photons can reflect and amplify the emission of photons, which can then exit the device as a collimated, coherent, monochromatic source of light - laser light.