FIGURE 3.3 (a) Space division multiplexing (SDM) using multi-core fiber. SOURCE: Reprinted, with permission, from Matsuo, S., K. Takenaga, Y. Arakawa, Y. Sasaki, S. Tanigawa, K. Saitoh, and M. Koshiba. 2011. Crosstalk behavior of cores in multi-core fiber under bent condition. IEICE Electronics Express 8(6):385-390. (b) Multi-mode fiber. SOURCE: Reprinted, with permission, from Ryf, R., S. Randel, A. Gnauck, C. Bolle, A. Sierra, S. Mumtaz, M. Esmaeelpour, E. Burrows, R. Essiambre, P. Winzer, D. Peckham, A. McCurdy, and R. Lingle. 2012. Mode-division multiplexing over 96 km of few-mode fiber using coherent 6×6 MIMO processing. IEEE Journal of Lightweight Technology 30:521-531. (c) Bit error rate performance and recovered data constellations of the quadrature-phase-shift-keying (QPSK) signal tributaries after SDM transmission using four spatial modes in a single few-mode fiber. SOURCE: Reprinted, with permission, from Al Amin, Abdullah, An Li, Simin Chen, Xi Chen, Guanjun Gao, and William Shieh. 2011. Dual-LP11 mode 4×4 MIMO-OFDM transmission over a two-mode fiber. Optics Express 19:16672-16679.