[1] [1] Li A, Chen X, Al Amin A, et al.. Space-division multiplexed high-speed superchannel transmission over few-mode fiber[J]. Journal of Lightwave Technology, 2012, 30(24): 3953-3964.

[2] [2] Zhang Yongsheng, Xie Zhiguo, Zheng Rongsheng, et al.. Mode coupling in polymer optical fiber and its enhancement to transmission bandwidth[J]. Chinese J Lasers, 2006, 33(9): 1234-1238.

[3] [3] Ryf R, Randel S, Gnauck A H, et al.. Space-division multiplexing over 10 km of three-mode fiber using coherent 6×6 MIMO processing[C]. Optical Fiber Communication Conference and Exposition (OFC/NFOEC), 2011 and the National Fiber Optic Engineers Conference, 2011: 1-3.

[4] [4] Randel S, Ryf R, Sierra A, et al.. 6×56-Gb/s mode-division multiplexed transmission over 33-km few-mode fiber enabled by 6×6 MIMO equalization[J]. Optics Express, 2011, 19(17): 16697-16707.

[5] [5] Gu Zhengtian, Lan Jinlong. Design optimization of coated long-period fiber grating based on mode transition[J]. Chinese J Lasers, 2014, 41(1): 0105007.

[6] [6] Gu Zhengtian, Lan Jinlong. Mode transition and refractive index response in long-period fiber grating coated with double-layer overlays including metal film[J]. Acta Optica Sinica, 2014, 34(4): 0406005.

[7] [7] Zhu Xiaoliang, Sun Weimin, Yan Qi. Investigation of astronomical fiber mode converter[J]. Acta Optica Sinica, 2014, 34(s1): s106003.

[8] [8] Chang Yuxin, Hu Guijun, Bai Song, et al.. Research of asymmetric planar waveguide type mode division multiplexer/demultiplexer[J]. Chinese J Lasers, 2014, 41(12): 1205004.

[9] [9] Genevaux P, Simonneau C, Labroille G, et al.. 6-mode spatial multiplexer with low Loss and high selectivity for transmission over few mode fiber[C]. Optical Fiber Communications Conference and Exhibition (OFC), 2015: W1A.5.

[10] [10] Birks T A, Mangan B J, Díez A, et al.. “Photonic lantern” spectral filters in multi-core fiber[J]. Optics Express, 2012, 20(13): 13996-14008.

[11] [11] Yerolatsitis S, Gris-Sánchez I, Birks T A. A diabatically-tapered fiber mode multiplexers[J]. Optics Express, 2014, 22(1): 608-617.