[1] D J Richardson, J M Fini, L E Nelson. Space-division multiplexing in optical fibres. Nat Photon, 7, 354-362(2013).
[2] P J Winzer. Making spatial multiplexing a reality. Nat Photonics, 8, 345-348(2014).
[3] R G H Van Uden, R A Correa, E A Lopez, F M Huijskens, C Xia et al. Ultra-high-density spatial division multiplexing with a few-mode multicore fibre. Nat Photonics, 8, 865-870(2014).
[4] T Mizuno, H Takara, A Sano, Y Miyamoto. Dense space-division multiplexed transmission systems using multi-core and multi-mode fiber. J Lightwave Technol, 34, 582-592(2016).
[5] Ryf R, Sierra A, Essiambre R J, Gnauck A H, Randel S et al. Coherent 1200-km 6x6 MIMO mode-multiplexed transmission over 3-core microstructured fiber. In Proceedings of 37th European Conference and Exhibition on Optical Communication 1-3 (IEEE, 2011).
[6] Gonda T, Imamura K, Sugizaki R, Kawaguchi Y, Tsuritani T. 125 μm 5-core fibre with heterogeneous design suitable for migration from single-core system to multi-core system. In Proceedings of 42nd European Conference on Optical Communication 1-3 (IEEE, 2016).
[7] Proceedings of Optical Fiber Communication Conference/National Fiber Optic Engineers Conference PDPB6 (Optical Society of America, 2011); https://doi.org/10.1364/OFC.2011.PDPB6.
[8] Proceedings of 38th European Conference and Exhibition of Optical Communication Th.3.C.1 (Optical Society of America, 2012); https://doi.org/10.1364/ECEOC.2012.Th.3.C.1.
[9] A Sano, H Takara, T Kobayashi, H Kawakami, H Kishikawa et al. 409-Tb/s + 409-Tb/s crosstalk suppressed bidirectional MCF transmission over 450 km using propagation-direction interleaving. Opt Express, 21, 16777-16783(2013).
[10] Proceedings of the 17th Opto-Electronics and Communications Conference 564-565 (IEEE, 2012); https://doi.org/10.1109/OECC.2012.6276573.
[11] A Van Newkirk, J E Antonio-Lopez, G Salceda-Delgado, M U Piracha, R Amezcua-Correa et al. Multicore fiber sensors for simultaneous measurement of force and temperature. IEEE Photonics Technol Lett, 27, 1523-1526(2015).
[12] K Saitoh, S Matsuo. Multicore fiber technology. J Lightwave Technol, 34, 55-66(2016).
[13] G M Saridis, D Alexandropoulos, G Zervas, D Simeonidou. Survey and evaluation of space division multiplexing: from technologies to optical networks. IEEE Commun Surveys Tuts, 17, 2136-2156(2015).
[14] W Klaus, J Sakaguchi, B J Puttnam, Y Awaji, N Wada et al. Free-space coupling optics for multicore fibers. IEEE Photonics Technol Lett, 24, 1902-1905(2012).
[15] Y Tottori, T Kobayashi, M Watanabe. Low loss optical connection module for seven-core multicore fiber and seven single-mode fibers. IEEE Photonics Technol Lett, 24, 1926-1928(2012).
[16] R R Thomson, H T Bookey, N D Psaila, A Fender, S Campbell et al. Ultrafast-laser inscription of a three dimensional fan-out device for multicore fiber coupling applications. Opt Express, 15, 11691-11697(2007).
[17] Y H Ding, F H Ye, C Peucheret, H Y Ou, Y Miyamoto et al. On-chip grating coupler array on the SOI platform for fan-in/fan-out of MCFs with low insertion loss and crosstalk. Opt Express, 23, 3292-3298(2015).
[18] B Zhu, T F Taunay, M F Yan, J M Fini, M Fishteyn et al. Seven-core multicore fiber transmissions for passive optical network. Opt Express, 18, 11117-11122(2010).
[19] Proceedings of the 17th Opto-Electronics and Communications Conference 475-476 (IEEE, 2012); https://doi.org/10.1109/OECC.2012.6276529.
[20] D Noordegraaf, P M W Skovgaard, M D Nielsen, J Bland-Hawthorn. Efficient multi-mode to single-mode coupling in a photonic lantern. Opt Express, 17, 1988-1994(2009).
[21] B R Li, Z H Feng, M Tang, Z L Xu, S N Fu et al. Experimental demonstration of large capacity WSDM optical access network with multicore fibers and advanced modulation formats. Opt Express, 23, 10997-11006(2015).
[22] Proceedings of Advanced Photonics SoM2G.3 (Optical Society of America, 2016); https://doi.org/10.1364/SOF.2016.SoM2G.3.
[23] J P Moore, M D Rogge. Shape sensing using multi-core fiber optic cable and parametric curve solutions. Opt Express, 20, 2967-2973(2012).
[24] Z Y Zhao, Z Y Liu, M Tang, S N Fu, L Wang et al. Robust in-fiber spatial interferometer using multicore fiber for vibration detection. Opt Express, 26, 29629-29637(2018).
[25] Z Y Zhao, M A Soto, M Tang, L Thévenaz. Distributed shape sensing using Brillouin scattering in multi-core fibers. Opt Express, 24, 25211-25223(2016).
[26] Proceedings of Optical Fiber Communication Conference Th1C.2 (Optical Society of America, 2015); https://doi.org/10.1364/OFC.2015.Th1C.2.
[27] https://technology.nasa.gov/media/Fiber_Optic_Shape_Sensing.pdf.
[28] Proceedings of the 44th AIAA Aerospace Sciences Meeting and Exhibit (AIAA, 2006); https://doi.org/10.2514/6.2006-624.
[29] http://spie.org/x15732.xml.
[30] B J Soller, D K Gifford, M S Wolfe, M E Froggatt. High resolution optical frequency domain reflectometry for characterization of components and assemblies. Opt Express, 13, 666-674(2005).
[31] R G Duncan, M E Froggatt, S T Kreger, R J Seeley, D K Gifford et al. High-accuracy fiber-optic shape sensing. Proc SPIE, 6530, 65301S(2007).
[32] Proceedings of Avionics and Vehicle Fiber-Optics and Photonics Conference 71-73 (IEEE, 2015); https://doi.org/10.1109/AVFOP.2015.7356646.
[33] Proceedings of Optical Fiber Sensors ThE42 (Optical Society of America, 2006); https://doi.org/10.1364/OFS.2006.ThE42.
[34] S T Kreger, D K Gifford, M E Froggatt, A K Sang, R G Duncan et al. High-resolution extended distance distributed fiber-optic sensing using Rayleigh backscatter. Proc SPIE, 6530(2007).
[35] M Froggatt, J Moore. High-spatial-resolution distributed strain measurement in optical fiber with Rayleigh scatter. Appl Opt, 37, 1735-1740(1998).
[36] Proceedings of Nonlinear Photonics JWA39 (Optical Society of America, 2007); https://doi.org/10.1364/BGPP.2007.JWA39.
[37] Proceedings of the 21st Annual Meeting of the IEEE Lasers and Electro-Optics Society 109-110 (IEEE, 2008); https://doi.org/10.1109/LEOS.2008.4688512.
[38] Askins C G, Miller G A, Friebele E J. Bend and twist sensing in a multiple-core optical fiber. In Proceedings of the Optical Fiber Communication Conference/National Fiber Optic Engineers Conference OMT3 (Optical Society of America, 2008).
[39] Proceedings of Imaging and Applied Optics AIMB2 (Optical Society of America, 2011); https://doi.org/10.1364/AIO.2011.AIMB2.
[40] E M Lally, M Reaves, E Horrell, S Klute, M E Froggatt. Fiber optic shape sensing for monitoring of flexible structures. Proc SPIE, 8345, 83452Y(2012).
[41] P S Westbrook, K S Feder, T Kremp, T F Taunay, E Monberg et al. Integrated optical fiber shape sensor modules based on twisted multicore fiber grating arrays. Proc SPIE, 8938, 89380H(2014).
[42] P S Westbrook, K S Feder, T Kremp, T F Taunay, E Monberg et al. Multicore optical fiber grating array fabrication for medical sensing applications. Proc SPIE, 9317, 93170C(2015).
[43] T Kremp, K S Feder, W Ko, P S Westbrook. Performance characteristics of continuous multicore fiber optic sensor arrays. Proc SPIE, 10058, 100580V(2017).
[44] P S Westbrook, T Kremp, K S Feder, W Ko, E M Monberg et al. Continuous multicore optical fiber grating arrays for distributed sensing applications. J Lightwave Technol, 35, 1248-1252(2017).
[45] Proceedings of Optical Fiber Communication Conference W1K.1 (Optical Society of America, 2018); https://doi.org/10.1364/OFC.2018.W1K.1.
[46] Proceedings of Advanced Photonics SeM4D.4 (Optical Society of America, 2016); https://doi.org/10.1364/SENSORS.2016.SeM4D.4.
[47] Proceedings of the 25th Optical Fiber Sensors 1-4 (IEEE, 2017); https://doi.org/10.1117/12.2267486.
[48] W H Li, X Y Bao, Y Li, L Chen. Differential pulse-width pair BOTDA for high spatial resolution sensing. Opt Express, 16, 21616-21625(2008).
[49] A Denisov, M A Soto, L Thévenaz. Going beyond 1000000 resolved points in a Brillouin distributed fiber sensor: theoretical analysis and experimental demonstration. Light Sci Appl, 5, e16074(2016).
[50] M N Alahbabi, Y T Cho, T P Newson. Simultaneous temperature and strain measurement with combined spontaneous Raman and Brillouin scattering. Opt Lett, 30, 1276-1278(2005).
[51] M Taki, A Signorini, C J Oton, T Nannipieri, F Di Pasquale. Hybrid Raman/Brillouin-optical-time-domain-analysis-distributed optical fiber sensors based on cyclic pulse coding. Opt Lett, 38, 4162-4165(2013).
[52] H F Martins, S Martin-Lopez, P Corredera, P Salgado, O Frazão et al. Modulation instability-induced fading in phase-sensitive optical time-domain reflectometry. Opt Lett, 38, 872-874(2013).
[53] Z Y Zhao, Y L Dang, M Tang, L Duan, M Wang et al. Spatial-division multiplexed hybrid Raman and Brillouin optical time-domain reflectometry based on multi-core fiber. Opt Express, 24, 25111-25118(2016).
[54] Proceedings of Asia Communications and Photonics Conference AW4I.3 (Optical Society of America, 2014); https://doi.org/10.1364/ACPC.2014.AW4I.3.
[55] Y Mizuno, N Hayashi, H Tanaka, Y Wada, K Nakamura. Brillouin scattering in multi-core optical fibers for sensing applications. Sci Rep, 5, 11388(2015).
[56] Z Y Zhao, Y L Dang, M Tang, B R Li, L Gan et al. Spatial-division multiplexed Brillouin distributed sensing based on a heterogeneous multicore fiber. Opt Lett, 42, 171-174(2017).
[57] Proceedings of Optical Fiber Communication Conference W3H.5 (Optical Society of America, 2017); https://doi.org/10.1364/OFC.2017.W3H.5.
[58] M A S Zaghloul, M H Wang, G Milione, M J Li, S P Li et al. Discrimination of temperature and strain in Brillouin optical time domain analysis using a multicore optical fiber. Sensors, 18(2018).
[59] Y Muanenda, C J Oton, S Faralli, T Nannipieri, A Signorini et al. Hybrid distributed acoustic and temperature sensor using a commercial off-the-shelf DFB laser and direct detection. Opt Lett, 41, 587-590(2016).
[60] Proceedings of Optical Fiber Communication Conference W2A.7 (Optical Society of America, 2018); https://doi.org/10.1364/OFC.2018.W2A.7.
[61] Z Y Zhao, Y L Dang, M Tang, L Wang, L Gan et al. Enabling simultaneous DAS and DTS through space-division multiplexing based on multicore fiber. J Lightwave Technol, 36, 5707-5713(2018).
[62] T Zhu, Q He, X H Xiao, X Y Bao. Modulated pulses based distributed vibration sensing with high frequency response and spatial resolution. Opt Express, 21, 2953-2963(2013).
[63] Z Y Zhao, M Tang, L Wang, N Guo, H Y Tam et al. Distributed vibration sensor based on space-division multiplexed reflectometer and interferometer in multicore fiber. J Lightwave Technol, 36, 5764-5772(2018).
[64] Y Koyamada, M Imahama, K Kubota, K Hogari. Fiber-optic distributed strain and temperature sensing with very high measurand resolution over long range using coherent OTDR. J Lightwave Technol, 27, 1142-1146(2009).
[65] X Lu, M A Soto, L Thévenaz. MilliKelvin resolution in cryogenic temperature distributed fibre sensing based on coherent Rayleigh scattering. Proc SPIE, 9157, 91573R(2014).
[66] J Pastor-Graells, H F Martins, A Garcia-Ruiz, S Martin-Lopez, M Gonzalez-Herraez. Single-shot distributed temperature and strain tracking using direct detection phase-sensitive OTDR with chirped pulses. Opt Express, 24, 13121-13133(2016).
[67] Y L Dang, Z Y Zhao, M Tang, C Zhao, L Gan et al. Towards large dynamic range and ultrahigh measurement resolution in distributed fiber sensing based on multicore fiber. Opt Express, 25, 20183-20193(2017).
[68] X G Sun, J Li, D T Burgess, M Hines, B Zhu. A multicore optical fiber for distributed sensing. Proc SPIE, 9098, 90980W(2014).
[69] http://en.yofc.com/.
[70] https://www.chiralphotonics.com/.
[71] http://www.optoscribe.com/.
[72] L Shen, L Gan, Z R Dong, B R Li, D M Liu et al. End-view image processing based angle alignment techniques for specialty optical fibers. IEEE Photonics J, 9, 1-8(2017).
[73] H H Diamandi, Y London, A Zadok. Opto-mechanical inter-core cross-talk in multi-core fibers. Optica, 4, 289-297(2017).
[74] G Bashan, H H Diamandi, Y London, E Preter, A Zadok. Optomechanical time-domain reflectometry. Nat Commun, 9, 2991(2018).
[75] D M Chow, Z S Yang, M A Soto, L Thévenaz. Distributed forward Brillouin sensor based on local light phase recovery. Nat Commun, 9, 2990(2018).
