Theory of the backscattering process in multimode optical fibers

Area of Science:

• Optical Fiber Communications
• Wave Propagation and Scattering

Background:

• Backscattering signatures in multimode fibers are complex and influenced by longitudinal parameter variations.
• Distinguishing intrinsic fiber loss from parameter fluctuations is crucial for accurate optical fiber characterization.

Purpose of the Study:

• To develop a theoretical framework predicting backscattered signatures from multimode fibers.
• To introduce and validate a novel excitation technique for unambiguous loss separation.

Main Methods:

• Formulating a theory based on the longitudinal variation of fiber characteristic parameters.
• Employing a novel excitation method termed 'mode-filtered excitation'.
• Conducting experimental verifications of the developed theory and excitation technique.

Main Results:

• The theory provides analytical results for backscattered signatures within a specific limit.
• Mode-filtered excitation enables the unambiguous separation of intrinsic loss from parameter fluctuations.
• Experimental results confirm the theory's predictions and the efficacy of the mode-filtering technique.

Conclusions:

• The presented theory accurately predicts multimode fiber backscattered signatures.
• Mode-filtered excitation is an effective technique for precise optical fiber loss assessment.
• This approach enhances the understanding and characterization of optical fibers.