Summary
International Conference on Emerging Technologies for Communications
2020
Session Number:IA1
Session:
Number:IA1-2
Interferometric technique for simultaneous measurement of the differential group delay between modes in few-mode fibers
Masaharu Ohashi, Nori Shibata, Hirokazu Kubota, Yuji Miyoshi,
pp.-
Publication Date:2020/12/2
Online ISSN:2188-5079
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Summary:
Increasing the information capacity of space-division-multiplexing (SDM) transmission employing few-mode multi-core fibers (FM-MCFs) and few-mode fibers (FMFs) is a topic of significant research interest. FMFs with low differential group delays (DGDs) and low mode coupling are required for mode-division multiplexing (MDM) transmission systems that employ multiple-input multiple-output (MIMO) processing. DGD between the guided modes, chromatic dispersion for each mode, and optical losses are important aspects to be taken into consideration in designing MDM systems. Hence, it is important to investigate DGD and chromatic dispersion characteristics in the 1260-1360 nm and 1450-1625 nm telecommunication bands. Several techniques to measure modal and chromatic dispersions have been reported previously. However, simultaneous measurement methods to estimate the DGD between the guided modes in FM-MCFs and FMFs need further investigation. In this study, we propose an interferometric technique for simultaneous measurement of DGD between the guided modes in the cores of FM-MCFs, and between any two modes in FMFs. The measurement principle is based on an investigation of a transmitted spectrum through temporal decomposition using a Fourier transform. We performed experiments on a two-core FM-MCF and a four-mode fiber to confirm the feasibility of the interferometric technique. Through the proposed technique, a simultaneous measurement of the DGD between two arbitrary modes of the FMF was successfully performed. This implies that our method is an effective and useful tool for measuring the DGD of both FMFs and FM-MCFs.