Teach Yourself Electricity and Electronics, Sixth Edition, 6th Edition

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CHAPTER

Lasers

THE WORD LASER IS AN ACRONYM THAT STANDS FOR THE TECHNICAL TERM LIGHT AMPLIFICATION by stimulated emission of radiation. Lasers have diverse applications in electronic systems.

How a Laser Works

In theory, laser radiation differs from ordinary EM radiation in two ways. First, all of the energy exists at a single wavelength, and therefore, at a single frequency. At visible-light wavelengths, this property gives the light a vivid hue (“color”). Second, the “wave packets” (known as photons) in a laser beam all propagate in phase coincidence, so all the wave peaks and troughs “line up” with one another. When we talk about lasers, we usually refer to devices that produce coherent rays in the ultraviolet (UV), visible-light, or infrared ...