196,818 research outputs found
Dataset for manuscript Non-destructive characterization of rare-earth-doped optical fiber preforms
No full textDataset supports:
Vivona, M., Kim, J. and Zervas, M. N. (2018). Non-destructive characterization of rare-earth-doped optical fiber preforms. Optics Letters.
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Dataset for Instrumentation for Simultaneous Non-Destructive Profiling of Refractive Index and Rare-Earth-Ion Distributions in Optical Fiber Preforms
No full textAssigned DOI: https://doi.org/10.5258/SOTON/D0701
Dataset supports:
Vivona, M. and Zervas, M. N. Instrumentation for Simultaneous Non-Destructive Profiling of Refractive Index and Rare-Earth-Ion Distributions in Optical Fiber Preforms. Publication in the journal Instruments.</span
Effects of random phase and amplitude errors in optical fiber Bragg gratings
No full textThis paper studies the influence of random phase and amplitude fabrication errors on the performance of optical filters based on fiber Bragg gratings (FBGs). In particular, we analyze two effects of particular importance for optical communications: the excess crosstalk induced in apodized gratings commonly used in wavelength-division-multiplexing (WDM) systems, and the time-delay fluctuations that appear in chirped gratings employed to compensate the fiber dispersion. A statistical model is presented to explain these effects in terms of the coherence length of the grating fabrication procedure
Enhanced pump absorption of active fiber components with skew rays
No full textWe propose a model and then demonstrate a technique that can be used to optimize pump absorption in active multimode fibers with different cladding geometries, by varying the angle of pump light excitation. The analysis of the contribution of different ray groups at different wavelengths enables the design optimization of active and passive fiber components in fiber lasers.George Y. Chen, Christophe A. Codemard, Michalis N. Zervas, Tanya M. Monro, and David G. Lancaste
Twisted Hi-Bi fiber DFB lasers with controllable output polarization
No full textWe demonstrate that single polarization, hi-bi fiber DFB lasers are in general characterized by elliptical state of polarization, due to the in-built fiber birefringence axis rotation. Externally applied birefringence-axis twist is shown to provide accurate control of the output SOP. Continuous tuning from circular to linear polarization, with PER of ~40dB has been demonstrated
5.6 kW peak power, nanosecond pulses at 274 nm from a frequency quadrupled Yb-doped fiber MOPA
No full textDataset for the paper:
He, J, Lin, D, Xu, L, Beresna, M, Zervas, M, Alam, S-U & Brambilla, G (2018) '5.6 kW peak power, nanosecond pulses at 274 nm from a frequency quadrupled Yb-doped fiber MOPA' in Optics Express
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Non-destructive coupler characterisation technique
No full textA novel nondestructive technique for characterising couplers by means of a local perturbation is described. The method is studied theoretically and verified experimentally by characterising different types of fused fiber-couplers. Using this technique, both the information of the power distribution and coupling profile along the coupler waist are obtained
Dataset for 'Overlapped pulsed pumping of tandem pumped fiber amplifiers to increase achievable pulse energy'
No full textDataset for the article:
A. Malinowski, J. H. V. Price and M. N. Zervas, "Overlapped Pulsed Pumping of Tandem Pumped Fiber Amplifiers to Increase Achievable Pulse Energy," in IEEE Journal of Quantum Electronics, vol. 53, no. 2, pp. 1-8, April 2017.
doi: 10.1109/JQE.2017.2657334
It has been reported previously that in the regime appropriate for amplifying femtosecond pulses using the chirped pulse amplification technique in Yb-fiber sources that sub-micro-second pulsed tandem pumping not only provides the thermal benefits of c.w. tandem pumping, but also enables strong suppression of ASE. In that case, the pump pulse preceded the signal pulse train. Here, we propose a tandem pumping scheme in rare-earth-doped fiber amplifiers, where a train of signal pulses is amplified by a pump pulse, which is almost exactly temporally overlapped. Simulations demonstrate that this can be used to create uniform gain across the signal pulse train, even at very high total pulse energies, where there would be significant gain shaping in the previous case. In addition, the pump is absorbed in a much shorter length, which increases the threshold for nonlinear effects and gain of greater than 26 dB is shown to be readily achievable in an amplifier as short as 1.5 m. This results in increased extractable energy before reaching the threshold for limiting nonlinear effects, such as stimulated Raman scattering. These attributes should be attractive for high energy, high average power, ultrashort pulse, coherently combined fiber laser systems.</span
A new design approach for fibre DFB lasers with improved efficiency
No full textThe standard DFB laser optimisation method is critically investigated and a new design approach based on the effective cavity length is presented. By applying this method in a Erbium-Ytterbium co-doped fibre, pump-to-signal conversion ratio is increased by 40% for the same total device length and pumping conditions. The laser with proposed design is produced and the theoretical results are verified by the experimental work
Fibre Bragg gratings for dispersion compensation in optical communications
No full textThe main activities and recent developments towards the implementation of meter-long, high-performance fibre grating dispersion compensators in the Optoelectronics Research Centre, Southampton University are reviewed. Performance requirements of fibre-Bragg-gratings dispersion compensators and their impact on transmission systems will be discussed. We will report on the characteristics of continuously chirped FBGs capable of compensating linear and third-order dispersion over ~10nm bandwidth. Finally, system results using chirped FBGs as dispersion compensators will be given
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