3 December 1980 Speckle In Optical Fibers
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With a sufficiently narrow source spectrum, and either fiber movement or source frequency shift, a changing speckle pattern exists at a multimode optical fiber output plane which results in signal power fluctuations known as "modal noise." For the case of a step-index optical fiber, we report the measurement and analysis of the speckle spatial frequency distribution as a function of fiber parameters, and the correlation of two speckle patterns as a function of source frequency difference. We show how knowledge of the frequency correlation function and the source spectrum can be used to determine the speckle contrast. Again for a step-index fiber, we report the analysis and measurement of the probability density function of the optical power received by a detector at the end of a fiber as a function of the speckle's contrast and including the possibility of spatial filtration of the speckle, as might occur at a misaligned connector.
© (1980) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Eric G. Rawson, Eric G. Rawson, Joseph W. Goodman, Joseph W. Goodman, "Speckle In Optical Fibers", Proc. SPIE 0243, Applications of Speckle Phenomena, (3 December 1980); doi: 10.1117/12.959282; https://doi.org/10.1117/12.959282

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