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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