IV. FUTURE TRENDS IN FIBER OPTICS
COMMUNICATION
Fiber optics communication is definitely the future of data
communication. The evolution of fiber optic communication
has been driven by advancement in technology and increased
demand for fiber optic communication. It is expected to
continue into the future, with the development of new and
more advanced communication technology. Below are some
of the envisioned future trends in fiber optic communication.
A. All Optical Communication Networks
An all fiber optic communication is envisioned which will be
completely in the optical domain, giving rise to an all optical
communication network. In such networks, all signals will be
processed in the optical domain, without any form of electrical
manipulation. Presently, processing and switching of signals
take place in the electrical domain, optical signals must first be
converted to electrical signal before they can be processed,
and routed to their destination. After the processing and
routing, the signals are then re-converted to optical signals,
which are transmitted over long distances to their destination.
This optical to electrical conversion, and vice versa, results in
added latency on the network and thus is a limitation to
achieving very high data rates.
Another benefit of all optical networks is that there will not be
any need to replace the electronics when data rate increases,
since all signal processing and routing occurs in the optical
domain [9]. However, before this can become a reality,
difficulties in optical routing, and wavelength switching has to
be solved. Research is currently ongoing to find an effective
solution to these difficulties.
B. Multi – Terabit Optical Networks
Dense Wave Division Multiplexing (DWDM) paves the way
for multi-terabit transmission. The world-wide need for
increased bandwidth availability has led to the interest in
developing multi-terabit optical networks. Presently, four
terabit networks using 40Gb/s data rate combined with 100
DWDM channels exists. Researchers are looking at achieving
even higher bandwidth with 100Gb/s. With the continuous
reduction in the cost of fiber optic components, the availability
of much greater bandwidth in the future is possible.
C. Intelligent Optical Transmission Network
Presently, traditional optical networks are not able to adapt to
the rapid growth of online data services due to the
unpredictability of dynamic allocation of bandwidth,
traditional optical networks rely mainly on manual
configuration of network connectivity, which is time
consuming, and unable to fully adapt to the demands of the
modern network. Intelligent optical network is a future trend
in optical network development [2], and will have the
following applications: traffic engineering, dynamic resource
route allocation, special control protocols for network
management, scalable signaling capabilities, bandwidth on
demand, wavelength rental, wavelength wholesale,
differentiated services for a variety of Quality of Service
levels, and so on. It will take some time before the intelligent
optical network can be applied to all levels of the network, it
will first be applied in long-haul networks, and gradually be
applied to the network edge [10].
D. Ultra – Long Haul Optical Transmission
In the area of ultra-long haul optical transmission, the
limitations imposed due to imperfections in the transmission
medium are subject for research. Cancellation of dispersion
effect has prompted researchers to study the potential benefits
of soliton propagation. More understanding of the interactions
between the electromagnetic light wave and the transmission
medium is necessary to proceed towards an infrastructure with
the most favorable conditions for a light pulse to propagate
[11].
E. Improvements in Laser Technology
Another future trend will be the extension of present
semiconductor lasers to a wider variety of lasing wavelengths
[12]. Shorter wavelength lasers with very high output powers
are of interest in some high density optical applications.
Presently, laser sources which are spectrally shaped through
chirp managing to compensate for chromatic dispersion are
available. Chirp managing means that the laser is controlled
such that it undergoes a sudden change in its wavelength when
firing a pulse, such that the chromatic dispersion experienced
by the pulse is reduced. There is need to develop instruments
to be used to characterize such lasers. Also, single mode
tunable lasers are of great importance for future coherent
optical systems. These tunable lasers lase in a single
longitudinal mode that can be tuned to a range of different
frequencies.
F. Laser Neural Network Nodes
The laser neural network is an effective option for the
realization of optical network nodes. A dedicated hardware
configuration working in the optical domain and the use of
ultra-fast photonic sections is expected to further improve the
capacity and speed of telecommunication networks [12]. As
optical networks become more complex in the future, the use
of optical laser neural nodes can be an effective solution.