[1] R. Essiambre, G. Kramer, P. J. Winzer, G. J. Foschini and B. Goebel, Journal of Lightwave Technology 28, 662 (2010).
[2] D. J. Richardson, J. M. Fini and L. E. Nelson, Nature Photonics 7, 354 (2013).
[3] G. Stepniak, L. Maksymiuk and J. Siuzdak, Journal of Lightwave Technology 29, 1980 (2011).
[4] Carlos Montero, Vicente Moreno, Xesús Prieto-Blanco, Eduardo F. Mateo, Ezra Ip, José Crespo and Jesús Li-.ares, Applied Optics 52, 2332 (2013).
[5] DAI Dao-xin and WANG Jian, IEEE Photonics Society News 28, 8 (2014).
[6] Nicolas K. Fontaine, Sergio G. Leon-Sava, Roland Ryf, Joel R. Salazar Gil, Burcu Ercan and Joss Bland-Hawthorn, Mode-Selective Dissimilar Fiber Photonic-Lantern Spatial Multiplexers for Few-Mode Fiber, European Conference and Exhibition on Optical Communication, 1 (2013).
[7] S. Savin, M. J. F. Digonnet, G. S. Kino and H. J. Shaw, Optics Letters 25, 710 (2000).
[8] S. Ramachandran, WANG Zhi-yong and YAN Man, Optics Express 27, 698 (2002).
[9] WANG Biao, ZHANG Wei-gang, BAI Zhi-yong, WANG Li, ZHANG Li-yu, ZHOU Quan, CHEI Lei and YAN Tie-yi, IEEE Photonics Technology Letters 27, 145 (2015).
[10] M. Sumetsky and S. Ramachandran, Optics Express 16, 402 (2008).
[11] MA Long, PEI Li, The Theory and Application of Overlapping Cascade Long-Period Fiber Grating, Bei-jing Jiaotong University, 2015. (in Chinese)
[12] JIANG Peng, BI Wei-hong, QI Yue-feng, FU Xing-hu, WU Yang and TIAN Peng-fei, Acta Physica Sinica 20, 204208-1 (2016). (in Chinese)
[13] DONG Jiang-li and CHIANG Kin-seng, IEEE Photon-ics Technology Letters 27, 1006 (2015).