[1] T Morioka. New generation optical infrastructure technologies: “EXAT initiative” towards 2020 and beyond [C]. Opto-Electronics and Communicaitons Conference, 2009. 1-2.

[2] R J Essiambre, G Kramer, P J Winzer, et al.. Capacity limits of optical fiber networks [J]. J Lightwave Technol, 2010, 28(4): 662-701.

[3] B Zhu, T F Taunay, M F Yan, et al.. Seven-core multicore fiber transmissions for passive optical network [J]. Opt Express, 2010, 18(11): 11117-11122.

[4] M Jinno, Y Miyamoto, Y Hibino. Optical-transport networks in 2015 [J]. Nature Photon, 2007, 1(3): 157-159.

[5] M Koshiba, K Saitoh, Y Kokubun. Heterogeneous multi-core fibers: proposal and design principle [J]. IEICE Electron Express, 2009, 6(2): 98-103.

[6] J M Fini, B Zhu, T Taunay, et al.. Crosstalk in multi-core optical fibres [C]. European Conference and Exposition on Optical Communications, 2011. M01.LeCervin.4.

[7] K Imamura, Y Tsuchida, K Mukasa, et al.. Investigation on multi-core fibers with large Aeff and low micro bending loss [J]. Opt Express, 2011, 19(11): 10595-10603.

[8] T Hayashi, T Taru, O Shimakawa, et al.. Ultra-low-crosstalk multi-core fiber feasible to ultra-long-haul transmission [C]. National Fiber Optic Engineers Conference, 2011. PDPC2.

[9] Gong Lingxian, Wang Chuncan, Chen Xue, et al.. Research of large mode area multi-core fibers with low bending loss [J]. Electro-Optic Technology Application, 2012, 27(5): 36-39.

[10] K Takenaga, S Matsuo, K Saitoh, et al.. Characterisation of MC fibers: new techniques and challenges [C]. Optical Fiber Communicaiton Conference, 2012. OTu1D.5.

[11] Zheng Siwen, Ren Guobin, Lin Zhen, et al.. Influence of trench parameters on the characteristic of trench-assisted multi-core fiber [J]. Acta Optica Sinica, 2013, 33(10): 1006001.

[12] K Imamura, H Inaba, K Mukasa, et al.. Multi core fiber with large Aeff of 140 μm2 and low crosstalk [C]. European Conference and Exhibition on Optical Communication, 2012. Mo.1.F.2.

[13] J Sakaguchi, B J Puttnam, W Klaus, et al.. 19-core fiber transmission of 19×100×172-Gb/s SDM-WDM-PDM-QPSK signals at 305 Tb/s [C]. National Fiber Optic Engineers Conference, 2012. PDP5C.1.

[14] M Bigot-Astruc, F Gooijer, N Montaigne, et al.. Trench-assisted profiles for large-effective-area single-mode fibers [C]. European Conference and Exhibition on Optical Communication, 2008. Mo.4.B.1.

[15] K Takenaga, Y Arakawa, S Tanigawa, et al.. Reduction of crosstalk by trench-assisted multi-core fiber [C]. Optical Fiber Communication Conference, 2011. OWJ4.

[16] Zhang Yu, Liu Zhihai, Yang Jun, et al.. An optical power coupling ratio control approach among multi-cores in a multi-core fiber [J]. Chinese J Lasers, 2011, 38(12): 1205002.