Design And Evaluation Of A Dual Core Erbium Doped Fiber Amplifier (Dc-Edfa)
Traditional erbium doped fiber amplifiers EDFA (unidirectional signaling) can only amplify signals propagating in a single direction, as some isolators must be installed to eliminate the reflections from end faces and fusion points. This means the amplifiers only amplify signal in one direction o...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English English |
| Published: |
2003
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/12172/1/FK_2003_30_A.pdf |
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| Summary: | Traditional erbium doped fiber amplifiers EDFA (unidirectional signaling) can only
amplify signals propagating in a single direction, as some isolators must be installed to
eliminate the reflections from end faces and fusion points. This means the amplifiers
only amplify signal in one direction over a fiber. For long haul transmission, many
amplifiers are placed along each single mode fiber. Total numbers of the amplifiers will
be the number of the amplifier over a fiber multiply by the number of the fibers in the
cable. This means a large number of amplifiers are required thus increasing a high cost.
In order to reduce the system cost, and increase the capacity, many studies have been
done using bi-directional signaling in a single fiber (duplex), through one or two
separate amplifiers.
In this work, a bi-directional signaling technique has been exploited, this in order to
amplify the signals bi-directionally, over two single mode fibers (unidirectional) . This is achieved by using two circulators instead of isolators at the terminals of the EDFA. The
main goal is to reduce the number of amplifiers in the optical communication system,
which results in a decrease in the system cost. The new system is tested by laboratory
experiments. From the results, it is found that the system has the same characterizations
as bi-directional EDFA amplifiers, (i.e. independent amplification, medium gain, low
ASE), as expected. Reflections also occur. The system has high reflection when the
difference in the input powers of the bidirectional signals is high. This causes different
gains and different amplified powers. The reflection of the signal which has higher input
power is associated with the other main signal (over the other fiber). The system shows
the best performance, when the difference in the input powers (for the two fibers) is
small and is even better when the bidirectional signals have the same input powers.
In conclusion, the project objectives have been achieved, and the system can reduce the
number of the amplifiers to as much as 50% of that in a unidirectional propagating
system, due to the fact that, two fibers can now share one amplifier and results in cost
reduction by almost 50%. Furthermore, the approach is flexible and simple. |
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