Experimental evaluation of nonlinear crosstalk in multi-core fiber

In this paper we evaluate experimentally and model theoretically the nonlinear crosstalk random process in multi-core fiber. The experimental results indicate that mode coupling in multi-core fibers is reduced in presence of fiber Kerr nonlinearities. An analytical study of the inter-core crosstalk probability density function in nonlinear regime is performed, where the theoretical distribution, derived from the nonlinear coupled-mode equation, is experimentally validated in homogeneous four-core fiber. The herein presented analysis includes the evaluation of the inter-core crosstalk probability density function, mean and variance evolution considering the optical power launched into the fiber.This work has been partly funded by Spain National Plan project MODAL TEC2012-38558-C02-01. A. Macho and M. Morant work was supported by BES-2013-062952 F.P.I. Grant and postdoc UPV PAID-10-14 program, respectively.Macho Ortiz, A.; Morant Pérez, M.; Llorente Sáez, R. (2015). Experimental evaluation of nonlinear crosstalk in multi-core fiber. Optics Express. 23(14):18712-18720. https://doi.org/10.1364/OE.23.01871218712187202314Essiambre, R.-J., Kramer, G., Winzer, P. J., Foschini, G. J., & Goebel, B. (2010). Capacity Limits of Optical Fiber Networks. Journal of Lightwave Technology, 28(4), 662-701. doi:10.1109/jlt.2009.2039464Eriksson, T. A., Puttnam, B. J., Luis, R. S., Karlsson, M., Andrekson, P. A., Awaji, Y., & Wada, N. (2015). Experimental Investigation of Crosstalk Penalties in Multicore Fiber Transmission Systems. IEEE Photonics Journal, 7(1), 1-7. doi:10.1109/jphot.2015.2397275Fini, J. M., Zhu, B., Taunay, T. F., & Yan, M. F. (2010). Statistics of crosstalk in bent multicore fibers. Optics Express, 18(14), 15122. doi:10.1364/oe.18.015122Fini, J. M., Zhu, B., Taunay, T. F., Yan, M. F., & Abedin, K. S. (2012). Crosstalk in multicore fibers with randomness: gradual drift vs short-length variations. Optics Express, 20(2), 949. doi:10.1364/oe.20.000949Koshiba, M., Saitoh, K., Takenaga, K., & Matsuo, S. (2011). Multi-core fiber design and analysis: coupled-mode theory and coupled-power theory. Optics Express, 19(26), B102. doi:10.1364/oe.19.00b102Hayashi, T., Taru, T., Shimakawa, O., Sasaki, T., & Sasaoka, E. (2012). Characterization of Crosstalk in Ultra-Low-Crosstalk Multi-Core Fiber. Journal of Lightwave Technology, 30(4), 583-589. doi:10.1109/jlt.2011.2177810Hayashi, T., Sasaki, T., Sasaoka, E., Saitoh, K., & Koshiba, M. (2013). Physical interpretation of intercore crosstalk in multicore fiber: effects of macrobend, structure fluctuation, and microbend. Optics Express, 21(5), 5401. doi:10.1364/oe.21.005401Jensen, S. M. (1982). The Nonlinear Coherent Coupler. IEEE Transactions on Microwave Theory and Techniques, 30(10), 1568-1571. doi:10.1109/tmtt.1982.1131291Fraile-Pelaez, F. J., & Assanto, G. (1990). Coupled-mode equations for nonlinear directional couplers. Applied Optics, 29(15), 2216. doi:10.1364/ao.29.002216Nazemosadat, E., & Mafi, A. (2013). Nonlinear switching in multicore versus multimode waveguide junctions for mode-locked laser applications. Optics Express, 21(25), 30739. doi:10.1364/oe.21.030739Li-Pen Yuan. (1994). A unified approach for the coupled-mode analysis of nonlinear optical couplers. IEEE Journal of Quantum Electronics, 30(1), 126-133. doi:10.1109/3.272070Ogusu, K., & Li, H. (2013). Normal-Mode Analysis of Switching Dynamics in Nonlinear Directional Couplers. Journal of Lightwave Technology, 31(15), 2639-2646. doi:10.1109/jlt.2013.2272467Yasumoto, K., Maeda, H., & Maekawa, N. (1996). Coupled-mode analysis of an asymmetric nonlinear directional coupler. Journal of Lightwave Technology, 14(4), 628-633. doi:10.1109/50.491402Huang, W.-P. (1994). Coupled-mode theory for optical waveguides: an overview. Journal of the Optical Society of America A, 11(3), 963. doi:10.1364/josaa.11.000963Hayashi, T., Taru, T., Shimakawa, O., Sasaki, T., & Sasaoka, E. (2011). Design and fabrication of ultra-low crosstalk and low-loss multi-core fiber. Optics Express, 19(17), 16576. doi:10.1364/oe.19.016576Koshiba, M., Saitoh, K., & Kokubun, Y. (2009). Heterogeneous multi-core fibers: proposal and design principle. IEICE Electronics Express, 6(2), 98-103. doi:10.1587/elex.6.9