1,721,020 research outputs found
Novel fibres for next-generation fibre-optic gyroscopes
No full textThe fibre-optic gyroscope (FOG) is one of the most successful optical fibre sensors in history and it has become a keystone technology for high-performance rotation sensing. Its core sensing element is a long optical fibre wound into a coil. Here, sensitivity to rotation scales in proportion with optical path length, and thus much FOG development has been directed toward deploying longer fibres within the same footprint. However, the fibre itself can be a major source of signal errors via Rayleigh backscattering, polarization cross-coupling, environmental effects, and non-linearity – thus, high-performance FOGs require advanced strategies to suppress these limitations in their multi-kilometer long sensing coils. This work explores two exciting fibre technologies which show great potential to address these challenges. The first is multicore optical fibre (MCF), in which multiple, independent optical waveguides (cores) are placed within the same glass cladding. These densely packed cores increase optical length, and thus gyro sensitivity, while preserving the coil geometry. This work details the construction of a fully functional interferometric FOG employing state-of-the-art MCF. This demonstrator uses a 7-core, 154 m long fibre coil, and through acquisition of detailed performance data, we realize the 7X sensitivity improvement conferred by use of MCF. The promise of MCF for FOGs is further highlighted by illustrating novel designs and improvements to existing FOG systems which are afforded by this signal density enhancement. The second fibre technology is hollow core antiresonant fibre (ARF), in which a glass microstructure confines signal light to the central hollow region of the fibre. Ultra-low interaction between light and glass renders the fibre orders of magnitude less sensitive to material and environmental effects. This work highlights several benefits of ARFs for FOGs, including the first-ever measurements of polarization coupling in long, symmetric ARFs. These data show that polarization in ARFs can be 2-3 orders of magnitude purer than the theoretical limit for solid fibres. It is further shown, through use of an advanced resonator FOG testbed, that ARFs are immune to many of the material-related guidance impairments which beleaguer solid core FOGs. Through the analysis and demonstrations presented here we show the great promise that these two novel fibres can offer future FOGs. This is a boon for existing and emerging FOG applications which require high-performance navigation in a compact format – from new concepts in robotics and autonomous vehicles which are beginning to shape our world, to the next-generation of space and submarine applications which will explore new worlds
Dataset supporting the University of Southampton Doctoral Thesis "Novel fibres for next-generation fibre optic gyroscopes"
No full textDataset supporting the University of Southampton Doctoral Thesis "Novel fibres for next-generation fibre optic gyroscopes".
This is an ensemble of all gyro data acquisition runs for the multicore IFOG (MCIFOG ) and the benchmark PM IFOG (Benchmark IFOG) described in the thesis. The conditions for each individual test data run is given in an excel workbook which tabulates all the relevant conditions for the run. The Readme file gives a further description of all the data files.
All data can be processed via the MATLAB scripts contained in the folder "Gyro Data Analysis".
Process data by updating the "main_dir" variable in the main script, "analyze_gyro_data_v8.m", to match the data folder which is to be processed.
The temperature log for a given run can be processed simultaneously by enabling the "use_thermal_data" option.
Descriptions of processing options and other analysis features is given in the comments of the MATLAB code.
A detailed description of the test configuration for each gyro run is given in the excel files:
"MCIFOG 1 Test Log.xlsx" and "PM Gyro Test Log.xlsx"
Some of the data included in this set is given in the following publication:
A. Taranta, A. Gillooly, V. I. Kopp, D. Neugroschl, M. Ibsen, C. Emslie, and J. Sahu, "Performance Characteristics of a Multicore Interferometric Fiber Optic Gyroscope Using a 7-Core Fiber," in 2020 DGON Inertial Sensors and Systems (ISS) (IEEE, 2020), pp. 1–20.
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Non-destructive structural characterisation of double nested antiresonant nodeless fiber
No full textWe present a side-scattering method for accurate, rapid and non-destructive measurement of double nested antiresonant nodeless fiber (DNANF) microstructure. The diameters of all nested tubular capillaries are measured with sub-micron accuracy.</p
Birefringence effects in fibre-based polarisation-insensitive FWM systems
No full textWe present a quantitative study of the effects of birefringence in polarisation-insensitive orthogonal-pump four-wave mixing (FWM) systems, that ultimately advises on appropriate fibre length selection for minimised polarisation dependent gain
Non-destructive characterization of hollow core fiber
No full textWe summarize our recent work developing a technique for accurate and non-destructive measurement of the microstructure geometry of nested and double nested antiresonant fibers. We present results showing microstructure variation along a 2.2 km fiber
Longitudinal non-destructive characterization of nested antiresonant nodeless fiber microstructure geometry and twist
No full textWe demonstrate non-destructive measurement of nested antiresonant nodeless fiber (NANF) microstructure along 2.2 km of fiber using a side-scattering method. Additionally, using the same technique, we demonstrate measurement of twisting in NANF.</p
Distributed measurement and modified Navier-Stokes model of gas pressure profile evolution in hollow-core antiresonant fibres
No full textRecent progress in reducing the loss of hollow-core fibres (HCFs) makes them great candidates for many fibre applications. However, as the fibre's optical properties depend on the gas pressure and composition within the core and cladding holes, it is essential to understand the gas dynamics at play when the fibres are pressurised, vented or evacuated. Here, we investigate the gas flow dynamics along the core of an HCF with a more complex microstructure design, as is typical of recent state-of-the-art HCFs. We use a novel distributed technique based on optical time-domain reflectometry (OTDR). This technique enables measurement of the evolution of the pressure distribution within the hollow core during the gas-filling process over long fibre lengths. Using these results, we show that the pressure distribution inside the HCF can be simulated using simplified Navier-Stokes equations and approximating the fibre core as a simple cylindrical tube of ∼ 0.7 times the fibre core diameter
Non-Invasive Measurement of Hollow-Core Antiresonant Fiber Structure
No full textWe describe and demonstrate an interferometric side-scattering technique for measuring the microstructure geometry of nested antiresonant hollow-core fiber (NANF). Using this technique, we are able to non-invasively measure the diameters of all the thin tubular capillaries in a NANF with sub-micron accuracy.</p
Quantitative study of birefringence effects in fiber-based orthogonal-pump FWM systems
No full textOptical fibres have unwanted residual birefringence due to imperfections infabrication processes and environmental conditions. This birefringence will randomize the state of polarization of propagating signals and may harm the performance of four-wave mixing based processing devices. Here, we present a quantitative study of the effects of birefringence in orthogonal-pump four-wave mixing systems, and identify different regions of operation of the optical fibre, mainly determined by the relative magnitude between the physical length 𝐿and beat length 𝐿𝑏. This finding clarifies the characteristics of the complex interplay between birefringence and four-wave mixing and advises appropriate fibre length selection for minimized polarization dependent gain.<br/
Bi-doped fibre lasers and wideband amplifiers in the 1150-1500nm band
No full textBismuth (Bi)-doped fibres paved the way to develop amplifiers and lasers in the 1150-1500nm wavelength range owing to its host dependent luminescence characteristics. Bi-doped aluminosilicate (BAS), phosphosilicate (BPS) and germanosilicate (BGS) fibres have shown luminescence around 1150nm, 1300nm and 1450nm, respectively. Here, we present the fabrication of Bi-doped fibres in aluminosilicate and phosphosilicate hosts by the MCVD-solution doping technique. Also, we present the amplifier and laser (CW and pulsed) performance in the fabricated Bi-doped fibres
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