Intrinsically Irreversible Multiphoton Laser Gain Mechanisms
نویسندگان
چکیده
Single-photon stimulated radiative interactions are universally symmetric relative to emission and absorption. We point out that certain multiphoton stimulated processes, whose completion is dependent on the spontaneous emission of at least one photon, do not behave analogously. The broken symmetry found in such cases invalidates simple correlations between population inversion and laser gain. [S0031-9007(97)02451-4]
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