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High-capacity Optical Communications Using OAM-based Space Division Multiplexing. Yongxiong Ren (yongxior@usc.edu) Advisor : Prof. Alan. E Willner Nov. 18th 2016.
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High-capacity Optical Communications Using OAM-based Space Division Multiplexing YongxiongRen (yongxior@usc.edu) Advisor: Prof. Alan. E Willner Nov. 18th 2016 Acknowledge my advisor Prof. Willner, my OCLab mates (Guodong, Yan, Nisar, Long, Zhe, Yinwen, Joe, C. Bao, and LPC) and all collaborators.
Why Space Division Multiplexing? 1Pb/s D. Richardson et al, Nature Photonics 7, 354-362 (2013). • The current capacity of fiber link is mainly limited by the nonlinearity. • The SDM could potentially provide the next big jump in transmission capacity, reaching Pbit/s scale transmission rate.
My Research Work on Communications using OAM Beams • Atmospheric turbulence effects on orbital angular momentum (OAM) beams • Upgraded to CLEO 2013 Invited • Turbulence compensation of OAM beams • FiO 2014 postdeadline paper • High-impact OSA journal: Optica • 120-meter free-space optical link using OAM beam multiplexing on EEB building roof • Top Scored Paper in OFC 2015 (1 out of ~100) • Free-space communications using OAM multiplexing combined with conventional spatial multiplexing • IEEE Globecom Best Paper Award
Orbital Angular Momentum (OAM) Beams : Concept 3-D Wavefront Intensity Phase Plane wave l = 0 (OAM = 0) OAM beam (OAM = +1) OAM = +2 The number of possible states is infinite A. M. Yao et al, Adv. in Opt. & Phot., 2011
OAM-based Space Division Multiplexing OAM= 1 A bunch of rings that are overlapped spatially Data Channel 1 OAM = 2 Data Channel 2 Free-space Data Channel 3 OAM = 3 • Laser beams with different OAM values are orthogonal and can be separated • Transmission capacity can be increased by the number of transmitted OAM modes.
OAM Applications − OAM Communications • System results have been reported for up to 100 Tbit/s data transmission. • Future application scenarios might include: back-haul, data center, building-to-building communications. • Previous demonstrations: distance~1-meter on optical tables without atmospheric turbulence effects. H. Huang et al, Optics Letters 2013 J. Wang et al, Nature Photonics 2012
1. OAM Propagation in Free Space: Atmospheric Turbulence Atmospheric Turbulence Transmitted OAM Distorted OAM Power Power Rotating Phase Plate 𝓵5 𝓵4 𝓵2 𝓵3 𝓵1 𝓵1 Turbulence Emulator OAM Modes OAM Modes Y.Renet al., CLEO2013 (Invited) • OAM beam experiences turbulence-induced distortion, which results in power loss and channel crosstalk. • The atmospheric turbulence is emulated in the lab environment by using rotating phase plates, obeying Kolmogorov spectrum statistics. Y. Ren, et al., Opt. Lett., 2014
2. Turbulence Compensation of OAM Beams • Conventional adaptive optics approach couldn’t work for OAM beam. • Intensity singularity of OAM beam makes it difficult • Use Gaussian beam as a pilot beam to detect wavefront distortion of Gaussian beam with a conversional wavefront sensor. Y. Ren et al., Opt. Lett., 2014 Y. Ren et al., Optica, 2014 Y. Ren, et al., Opt. Lett., 2015
2. Experiment Results— Far Field Intensity Before compensation After compensation • By using the correction pattern obtained from a Gaussian probe beam in adaptive optical system, the distorted OAM beams up to OAM l=9are efficiently compensated. Y. Ren, et al., Opt. Lett., 2014
3. Longer-distance Transmission using OAM Multiplexing • Two mirrors placed 30-m away are used to reflect the OAM beams twice, thus the link distance is 120-meter. Y. Ren, et al., OFC, 2015 (Top Scored) • Four OAM modes (ℓ = ±1, ±3), each carrying a 100-Gbit/s QPSK data channel are transmitted, thus allowing a total capacity of 400-Gbit/s.
4. OAM Multiplexing + Conventional Spatial Multiplexing (MIMO) System MIMO: Multiple-input Multiple output • The system consists of N transmitter/receiver aperture pairs and each transmitter aperture contains M OAM modes, potentially providing N×M channels. • The complexity of implementing N×M channels could be less compared to a pure OAM system or MIMO system, and the system performance could potentially be enhanced. Y. Ren, et al., IEEE Globecom 2015 Best Paper Award
Selected Publications • 45 journal papers (including Science, Nat. Photonics, Nat. Communications, Opticaand Scientific Reports) and 67conference proceedings • Selected first-authored papers: • 1. Y. Ren, et al.,Scientific Reports, vol. 40, no. 18, pp. 4190-4193, 2016. • 2. Y. Ren, et al., Optics Letters, vol. 40, no. 10, pp. 2249-2252, 2016. • 3. Y. Ren, et al.,Optica, vol. 1, no. 6, pp. 376-382, 2016. • 4. Y. Ren, et al.,Optics Letters, vol. 40, no. 18, pp. 4190-4193, 2015. • 5. Y. Ren, et al., Optics Letters, vol. 40, no. 10, pp. 2249-2252, 2015. • 6. Y. Ren, et al.,Optica, vol. 1, no. 6, pp. 376-382, 2014. • 7. Y. Ren, et al.,Optics Letters, vol. 39, no. 10, pp. 2845-2848, 2014. • 8. Y. Ren, et al.,Optics Letters, vol. 38, no. 20, pp. 4062-4065, 2013. • 9. Y. Ren , et al.,OFC 2014. *Top scored paper* • 10. Y. Ren, et al., IEEE Globecom2014. *2014 Globecom Best Paper Award* • 11. Y. Ren, et al.,Frontiers in Optics (FiO) 2013. *FiOpostdeadline paper 2013* • 12. Y. Ren, et al.,Invited Paper, CLEO 2013. *Upgraded to invited status*
Thank You!!!! yongxior@usc.edu MHI Research Festival, Nov. 11th 2016