Electronic Equalization of Multikilometer 10-Gb/s Multimode Fiber Links: Mode-Coupling Effects

Balemarthy, K.; Polley, A.; Ralph, Stephen E.

doi:10.1109/jlt.2006.884988

Cited by 42 publications

(19 citation statements)

References 13 publications

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“…Here, we focus on the temporal response of the POF and together with a comprehensive multimode fiber (MMF) model [6] demonstrate that very small DMD of GI-POF can be explained by the large mode coupling strength [3,4]. Furthermore, we also demonstrate for the first time, that large deviations in the refractive index profile which produce unacceptably large DMD in glass MMF are dramatically reduced with strong mode coupling typically found in GI-POF.…”

Section: Introductionmentioning

confidence: 83%

“…Impulse response, differential modal delay (DMD) and bit-error-rate measurements have all shown that 200m graded index POF (GI-POF) links are capable of 40Gbps performance [2]. Previous observations of the spatial evolution of the mode power distribution [3,4] have sought to establish the relative contributions of mode coupling (MC) and differential modal attenuation (DMA) in GI-POF [5].Here, we focus on the temporal response of the POF and together with a comprehensive multimode fiber (MMF) model [6] demonstrate that very small DMD of GI-POF can be explained by the large mode coupling strength [3,4]. Furthermore, we also demonstrate for the first time, that large deviations in the refractive index profile which produce unacceptably large DMD in glass MMF are dramatically reduced with strong mode coupling typically found in GI-POF.…”

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confidence: 99%

“…Experimentally and numerically the initial mode power distributions correspond to single mode fiber (SMF) excitation. The mode coupling coefficients (MCC) among different mode groups are computed for a range of mode coupling strength parameter [6]. An effective MCC, given by the average MCC of all mode groups is used as a figure of merit although it is known that the mode coupling increases with mode number.…”

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confidence: 99%

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Mode coupling: Why POF Supports 40Gbps

Polley

Balemarthy

Ralph

2007

2007 Conference on Lasers and Electro-Optics (CLEO)

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We demonstrate experimentally and numerically that mode-coupling in graded index plastic optical fiber enables 40Gbps over 200m in the presence of dramatic refractive index errors. IntroductionPlastic optical fiber (POF) is fast emerging as a medium for high-bandwidth, short reach links [1]. Impulse response, differential modal delay (DMD) and bit-error-rate measurements have all shown that 200m graded index POF (GI-POF) links are capable of 40Gbps performance [2]. Previous observations of the spatial evolution of the mode power distribution [3,4] have sought to establish the relative contributions of mode coupling (MC) and differential modal attenuation (DMA) in GI-POF [5].Here, we focus on the temporal response of the POF and together with a comprehensive multimode fiber (MMF) model [6] demonstrate that very small DMD of GI-POF can be explained by the large mode coupling strength [3,4]. Furthermore, we also demonstrate for the first time, that large deviations in the refractive index profile which produce unacceptably large DMD in glass MMF are dramatically reduced with strong mode coupling typically found in GI-POF. Thus we establish the basis for 40Gbps capability in POF and quantify the strength of coupling needed to improve bandwidth in both POF and glass MMF. Modeling and resultsThe MMF model includes a mode solver and a split-step implementation of the mode coupling theory applicable for MC arising from random perturbation in the MMF [7]. The mode solver provides the transverse mode profiles, the group delays of the propagating modes in fiber with arbitrary size and arbitrary refractive index profiles. We examine a pure α-profile, although not optimum profile [8], to demonstrate sensitivity to index profile irregularities. Experimentally and numerically the initial mode power distributions correspond to single mode fiber (SMF) excitation. The mode coupling coefficients (MCC) among different mode groups are computed for a range of mode coupling strength parameter [6]. An effective MCC, given by the average MCC of all mode groups is used as a figure of merit although it is known that the mode coupling increases with mode number. The mode coupling length (MCL) is the distance required to reach a near steady-state mode power distribution [7]. The highest order mode group consists of leaky modes and a modal attenuation is assumed for them.The measured temporal response of 200m 50µm core GI-POF is depicted in Fig. 1a. Numerically computed responses using the MMF model without coupling and with typical POF coupling are shown in Fig 1b. and 1c. In both cases the excitation, 800nm 16ps FWHM, is scanned across the core diameter.The receiver is a commercial 50µm MMF detector followed by a digital sampling scope with a net bandwidth of 25GHz. The DMD, the maximum temporal width (at 25% of peak power) between all offsets is measured to be 66 ps with only 2ps maximum delay between peaks [ Fig. 1a]. This response is suitable for 40Gbps links.

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Section: Introductionmentioning

confidence: 83%

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confidence: 99%

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confidence: 99%

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Mode coupling: Why POF Supports 40Gbps

Polley

Balemarthy

Ralph

2007

2007 Conference on Lasers and Electro-Optics (CLEO)

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“…Different from an optical fiber transmission system with single stage DFE for single mode fiber, we applied the concept of DFE to the local optical network CWDM system with MMF [7]. Besides, we expand the concept of multistage DFE into the local optical network CWDM system with MMF [8,9].…”

Section: Combination Of Offset-launch and Dfe In Mmf Cwdm Systemmentioning

confidence: 99%

Performance evaluation on high-speed multi-channel CWDM system by using offset-launch method and multi-stage decision feedback equalizer

Chen

2011

IEICE Electron. Express

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“…Unlike silica fibers where the mode coupling is relatively weak [2], POF exhibits strong mode coupling. Indeed, the coupling length in large core PMMA POF is reported to be 20 to 50 m [3].…”

Section: Mode Couplingmentioning

confidence: 99%