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| | eMedicine - Lasers, General Principles and Physics : Article by Steve Lee, MD (Site not responding. Last check: 2007-11-07) |
 | | The theoretic principles behind the laser were developed as early as 1917, when Einstein laid the groundwork for stimulated emission in his treatise "On the Quantum Theory of Radiation." In 1955, Gordon produced the maser, the microwave predecessor of the laser. |
 | | This energy is in the form of an intense beam of monochromatic (same wavelength), collimated (parallel, nondiverging), and coherent (same direction) light (see Image 4). |
 | | A CW laser is generated by continuously pumping energy into the active medium to achieve an equilibrium between the number of atoms raised to the excited state and the number of photons emitted. |
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