| Author: | Zhang, Jianbo |
| Title: | High capacity short-reach optical transmission system based on fiber-eigenmode multiplexing |
| Advisors: | Lu, Chao (EEE) |
| Degree: | Ph.D. |
| Year: | 2023 |
| Subject: | Optical communications Fiber optics Hong Kong Polytechnic University -- Dissertations |
| Department: | Department of Electrical and Electronic Engineering |
| Pages: | xxvi, 119 pages : color illustrations |
| Language: | English |
| Abstract: | The fast development of bandwidth-hungry services is catalyzing the explosion of data in the current information and artificial intelligence (AI) era. Accordingly, the meteoric-growth capacity requirement has brought out the need to continuously accelerate the transmission rate to keep pace with the rapid-increasing traffic flow. Modedivision multiplexing (MDM), as an implementation of space-division multiplexing (SDM) technologies, is regarded as a promising solution to cope with the capacity crisis in fiber-based communication systems. Potentially, MDM can significantly increase the capacity of optical systems by multiplying the capacity of a single-mode fiber by the number of co-transmitted modes. Vector modes (VMs) are the full-vectorial eigenmodes supported by circular-core fibers. As true fiber-eigenmodes, VM-based MDM fiber transmission has captured much research interest recently. This thesis focuses on the studies of VM-based MDM short-reach optical transmission. The primary characteristic of fiber eigenmode is first investigated based on the high-order Poincaré sphere model. Then, the propagation characteristic of VM through free space and few-mode fiber (FMF) is studied. For free-space optical (FSO) transmission, the travel behavior of four VMs multiplexing-based link is evaluated under three atmospheric turbulence conditions. For FMF transmission, VM characteristic along the FMF transmission is simulated and presented. Based on VMs, two types of MDM short-reach fiber links, including uni-directional and bi-directional transmissions are demonstrated. For uni-directional transmission, two MDM links over 5 km FMF, including two VMs of the same order multiplexing transmission with 360 Gbit/s total capacity and two VMs of different orders multiplexing transmission with 400 Gbit/s total capacity are demonstrated based on Kramers-Kronig (KK) receiver, respectively. For bi-directional transmission, two MDM full-duplex bi-directional architectures including symmetrical and asymmetrical transmissions based on dual-VMs multiplexing over 3 km FMF are respectively implemented based on coherent detection and 2 × 2 MIMO. Firstly, four VMs, each carrying 14 GBaud quadrature phase-shift keying (QPSK) signal, is simultaneously employed on two terminals and a 224 Gbit/s homo-modal bi-directional transmission is demonstrated. To strengthen the immunity against backscattering crosstalk, hetero-modal bidirectional transmission is proposed, in which two VMs of l = 0 and two VMs of l = +2 are respectively utilized in the uplink and downlink and a 448 Gbit/s bi-directional transmission with 28 GBaud 16-ary quadrature amplitude modulation (QAM) modulation is realized. Furthermore, by combining with WDM technology, a 1.792 Tbit/s VM-based WDM-MDM full-duplex bi-directional transmission is also achieved. Next, a versatile scheme of MG filter for mode-group division multiplexing (MGDM) IM/DD transmission is proposed and experimentally demonstrated over 5 km FMF in a 152 Gbit/s MIMO-free IM/DD MGDM dual-channel simultaneous transmission and detection system. The bit error ratios (BERs) of each channel are below 7% hard-decision forward error correction (HD-FEC) threshold under both static and dynamic tests. Finally, unlike most MIMO-based SDM/MDM demonstrations without consideration of singular problems, non-Singular MIMO DSP based on multi-user constant modulus algorithm (MU-CMA) is implemented on the four-VMs-multiplexed KK reception system with an aggregate rate of 448 Gbit/s. None of the singular phenomena is observed under both static and dynamic performance evaluation. |
| Rights: | All rights reserved |
| Access: | open access |
Copyright Undertaking
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
- I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.
Please use this identifier to cite or link to this item:
https://theses.lib.polyu.edu.hk/handle/200/12666