Optical Fiber Technology 61 (2021) 102389
Available online 9 December 2020
1068-5200/© 2020 Published by Elsevier Inc.
Modes power equalization based-singular value decomposition in mode
division multiplexing systems for multi-hungry bandwidth applications
Yousef Fazea
a, *
, Angela Amphawan
b
, Y.A. Al-Gumaei
c
, Ahmed M. Al-Samman
d
,
Waleed Mugahed Al-Rahmi
e
a
Internetworks Research Laboratory, School of Computing, Universiti Utara Malaysia, 06010 Sintok, Kedah Darulaman, Malaysia
b
Massachusetts Institute of Technology, Cambridge, MA, USA
c
Department of Computer and Information Science, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne NE1 8ST, UK
d
Department of Manufacturing and Civil Engineering, Norwegian University of Science and Technology, 2815 Gjøvik, Norway
e
Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia
A R T I C L E INFO
Keywords:
SVD
MDM
Equalization
Compensation
ABSTRACT
Optical fiber tendencies are pushing for changes towards upgrading scalability, agility, and unwavering quality
for multi-hungry bandwidth applications. In the quest for future proof of those multi-hungry bandwidth appli-
cations, is vital to take advantage of new multiplexing technologies as the surge of network traffic that soon will
overwhelm the capacity of multimode fiber (MMF). Due to the issue of MMF modal dispersion and mode
coupling that caused Intersymbol Interference (ISI) which result in bandwidth degradation and limited range of
length. Thus, Mode division-multiplexing (MDM) is a significant and elegant emerging technology, which har-
nesses the symmetry of modes by transmitting in parallel data through different modes. This paper models and
analysis novel four-mode group demultiplexing MDM-based Singular Value Decomposition (SVD) to isolate the
signals and fairly distribute the power to the system sub-channels, each to their respective groups. The novel
MDM based-SVD system achieved an aggregated data rate of 100 Gbit/s on wavelengths 1550.12 nm over an
existed graded-index MMF length of 3000 m. The performance of the proposed system has been evaluated
through channel impulse response, channel spectrum, eye diagram, and Bit-Error-Rate (BER) matrices.
1. Introduction
The tremendous growth of connected devices and the continuous
demands of multi-hungry-bandwidth applications along with the
breakthrough of cloud computing and the Internet of Things (IoT) are
urging researchers worldwide to look for new multiplexing technologies
that are able to accommodate the surge of network traffic that will soon
overwhelm the capacity of multimode fiber (MMF) backbones. How-
ever, modal dispersion and mode coupling cause Intersymbol Interfer-
ence (ISI), which is considered as the primary impairment of MMF as it
results in bandwidth degradation and a limited range. Mode division
multiplexing (MDM) has been characterized as an elegant way to capi-
talize on orthogonal spatially overlapping and co-propagation of modes
[1,2]. In MDM, modes are transmitted in parallel streams carrying the
data independently, and then de-multiplexed in low intermodal cross-
talk. Controlling the excitation of modes will help to optimize the
channel impulse response such that the differential mode delay and
crosstalk will be minimized [3]. Long- Period Fiber Grating (LPFG)
utilizing CO
2
laser technique as in [4] transformed two-mode fiber
(TMF) by means of employing a direct CO
2
laser writing method to
fabricate LPFG. This method is one of two approaches in producing
modes directly from the laser cavity [5] whereby, the CO
2
laser can be
programmed to generate the needed grating profile. It has been proved
that the usage of LPFG is an efficient transverse mode selector once the
laser operates within a narrow spectrum [6,7]. In addition, other tech-
niques based on LPFG such as the thermal induction technique as in [8].
The thermal induction technique has been used as a simple method to
have an efficient and stabilized mode convertor from LP01to LP11
,
followed by mechanical pressure technique as in [9]. The conversion of
the mode can be feasible through a periodic grating structure, which
induced by mechanical pressure technique. Moreover, electromagnetic
induction technique as in [10] has been reported as a method to change
the loss amplitude of the LPFG. Without moving the phase-matching
wavelength, the conversion can be realized efficiently surpassing the
* Corresponding author.
E-mail address: yosiffz@uum.edu.my (Y. Fazea).
Contents lists available at ScienceDirect
Optical Fiber Technology
journal homepage: www.elsevier.com/locate/yofte
https://doi.org/10.1016/j.yofte.2020.102389
Received 27 July 2020; Received in revised form 28 October 2020; Accepted 28 October 2020