[1] Sillard P, Benyahya K et al. Few-mode fiber technology, deployments, and systems[J]. Proceedings of the IEEE, 110, 1804-1820(2022).

[2] Khonina S N, Kazanskiy N L, Butt M et al. Optical multiplexing techniques and their combination for on-chip and optical fiber communication: a review[J]. Opto-Electronic Advances, 5, 210127(2022).

[3] Du J B, Shen W H, Liu J C et al. Mode division multiplexing: from photonic integration to optical fiber transmission[J]. Chinese Optics Letters, 19, 091301(2021).

[4] Kobayashi T, Nakamura M, Hamaoka F et al. 1-Pb/s (32 SDM/46 WDM/768 Gb/s) C-band dense SDM transmission over 205.6-km of single-mode heterogeneous multicore fiber using 96-gbaud PDM-16QAM channels[C](2017).

[5] Soma D, Wakayama Y, Beppu S et al. 10.16-peta-B/s dense SDM/WDM transmission over 6-mode 19-core fiber across the C+L band[J]. Journal of Lightwave Technology, 36, 1362-1368(2018).

[6] Luís R S, Rademacher G, Puttnam B J et al. 1.2 Pb/s throughput transmission using a 160 μm cladding, 4-core, 3-mode fiber[J]. Journal of Lightwave Technology, 37, 1798-1804(2019).

[7] Rademacher G, Luís R S, Puttnam B J et al. High-capacity and long-haul transmission with space-division multiplexing[C], W7D. 1(2021).

[8] Rademacher G, Luís R S, Puttnam B J et al. Comparative study of few-mode and coupled-core multicore fiber transmissions[J]. Journal of Lightwave Technology, 40, 1590-1596(2022).

[9] Chen J K, Hu G J, Han Y Y. Communication experimental system with 3×3 mode division multiplexing based on photonic lanterns[J]. Chinese Journal of Lasers, 44, 1106009(2017).

[10] Chen J, Huang Q Q, Zhang Q W et al. Orthogonal frequency division/mode division multiplexing IM-DD multimode fiber transmission system based on photonic lanterns[J]. Acta Optica Sinica, 38, 0606008(2018).

[11] Hu T, Li J H, Ge D W et al. Weakly-coupled 4-mode step-index FMF and demonstration of IM/DD MDM transmission[J]. Optics Express, 26, 8356-8363(2018).

[12] Zhu Z Y, Zhao M X, Zhang Y C et al. MIMO equalization technology is based on neural networks in a high-speed IM-DD mode-division multiplexing transmission system[J]. Acta Optica Sinica, 41, 1406003(2021).

[13] Wu T, Tian F, Yang L J. Few-mode fiber transmission system based on probability shaping and interleaved encoding[J]. Acta Optica Sinica, 42, 0706006(2022).

[14] Yu J, Chi N, Chen L[M]. Coherent optical communication technology based on digital signal processing(2013).

[15] Kong M, Li X Y, Zhang J et al. High spectral efficiency of 400 Gb/s transmission using different modulation formats and advanced DSP[J]. Journal of Lightwave Technology, 37, 5317-5325(2019).

[16] Yu J J, Chi N[M]. Digital signal processing in high-speed optical fiber communication principle and application (I): single carrier modulation(2017).

[17] Yu J J, Chi N[M]. Digital signal processing in high-speed optical fiber communication principle and application (II): multi-carrier modulation and artificial intelligence(2018).