| | Definition: equilibrium mode distribution (Site not responding. Last check: 2007-10-23) |
 | | equilibrium mode distribution (EMD): That condition in a multimode fiber wherein after propagation has taken place for a certain distance, called the " equilibrium length," the relative power distribution among modes becomes statistically constant and remains so for the course of further propagation down the fiber. |
 | | Note 2: After the equilibrium length has been traversed, the numerical aperture of the fiber's output is independent of the numerical aperture of the optical source, i.e., beam, that drives the fiber. |
 | | Note 3: In the ray-optics analogy, the equilibrium mode distribution may be loosely thought of as a condition in which the "outermost rays" in the fiber core are stripped off by such phenomena as microbends, and only the "innermost rays" continue to propagate. |
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