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Investigation of fibre optical parametric amplifiers in telecommunications. / Mehdi Jamshidi Far
Swansea University Author: Mehdi Jamshidi Far
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Abstract
Fibre optical parametric amplifiers have been attracting much attention since their first demonstrations. They are capable of providing a high amount of gain over large bandwidth ranges. Since what we call a fibre optical parametric amplifier is technically a combination of one or two pumps and a su...
| Published: |
2010
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa42681 |
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| Abstract: |
Fibre optical parametric amplifiers have been attracting much attention since their first demonstrations. They are capable of providing a high amount of gain over large bandwidth ranges. Since what we call a fibre optical parametric amplifier is technically a combination of one or two pumps and a suitable highly-nonlinear fibre, their evolution is closely dependent on the improvements in the highly-nonlinear fibre technology and on that of the pumps. Recently, the advent of silica-based highly-nonlinear fibres with proper dispersion characteristics and the availability of high-power erbium-doped fibre amplifiers capable of delivering several Watts of continuous-wave power have led to great improvements in achieving better performances with fibre optical parametric amplifiers. The fibre length required is reduced and fibre optical parametric amplifiers can be operated in the continuous-wave regime, which is necessary for being useful in telecommunications. This work is a report of an investigation of different aspects of fibre optical parametric amplifiers. After reviewing the fundamentals of the operation of this kind of amplifiers, the difficulties facing them are discussed. Among these issues, the problem of nonlinear cross-talk is investigated in more details. 1 experimentally proved that by reducing fibre length, it is possible to keep the crosstalk in a tolerable range. The amplification of 26 communication channels modulated at about 40 Gb/s aggregating to the total capacity of more than 1 Tb/s, while obtaining performance results comparable to those of erbium-doped fibre amplifiers may tone down the chief criticism on the parametric amplifiers. Two amplifiers with a record gain (60 dB for a two-pump amplifier) and a record bandwidth (270 nm in a one-pump amplifier) were demonstrated and it has been shown that there might be possibilities for improving the adverse effect of the Raman gain on the flatness of the gain spectra of the parametric amplifiers at the expense of losing some gain. A sample of a newly-developed bismuth-oxide highly-nonlinear fibre is used to construct a novel scheme for wavelength demultiplexing, and the possibility of simultaneous time- and wavelength demultiplexing is discussed. |
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| Keywords: |
Electrical engineering. |
| College: |
Faculty of Science and Engineering |