Fabrication and Applications of Low OH Photonic Crystal Fibres

The aim of this thesis is to consistently fabricate low OH content silica solid-core photonic crystal fibres of different core diameters, identified as low spectral attenuation at 1383 nm. Three different methods are proposed. Two of them are focused on preventing the OH contamination of glass during fabrication whilst the third method is focused on obtaining low OH fibres by reducing the OH content of already contaminated glass. The local attenuation at the ends of these low OH fibres is notoriously worsen when they are exposed to the atmospheric water vapour, the levels of this attenuation depending very strongly with core diameter. The low OH levels achieved (0.19 ppm) in the small-core photonic crystal fibres open the scope to applications in non linear optics where standard levels of absorption are detrimental. In particular, the principle of a widely tunable source (across the OH absorption peak at 1383 nm) delivering femtosecond pulses beyond 2 μm is demonstrated experimentally.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Dataset for "The Airy fibre: an optical fibre that guides light diffracted by a circular aperture"

data used in the preparation of the paperThe methodology for this study is described in the paper

Characterizing the variation of propagation constants in multicore fibre

We demonstrate a numerical technique that can evaluate the core-to-core variations in propagation constant in multicore fibre. Using a Markov Chain Monte Carlo process, we replicate the interference patterns of light that has coupled between the cores during propagation. We describe the algorithm and verify its operation by successfully reconstructing target propagation constants in a fictional fibre. Then we carry out a reconstruction of the propagation constants in a real fibre containing 37 single-mode cores. We find that the range of fractional propagation constant variation across the cores is approximately $\pm2 \times 10^{-5}$.Comment: 17 pages; preprint format; 5 figures. Submitted to Optics Expres

Multi-core fibre-fed integral field spectrograph (MCIFU) IV:The fiber link

The Multi-Core Integral-Field Unit (MCIFU) is a diffraction-limited near-infrared integral-field spectrograph designed to detect and characterise exoplanets and disks in combination with extreme adaptive optics (xAO) instruments. It has been developed by an extended consortium as an experimental path finder for medium resolution spectroscopic upgrades for xAO systems. To allow it to achieve its goals we manufactured a fibre link system composed of a custom integrated fiber, with 3D printed microlenses and an ultrafast laser inscribed reformatter. Here we detail the specific requirements of the fibre link, from its design parameters, through its manufacture the laboratory performance and discuss upgrades for the future. © 2020 SPIE.Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

An innovative integral field unit upgrade with 3D-printed micro-lenses for the RHEA at Subaru

In the new era of Extremely Large Telescopes (ELTs) currently under construction, challenging requirements drive spectrograph designs towards techniques that efficiently use a facility's light collection power. Operating in the single-mode (SM) regime, close to the diffraction limit, reduces the footprint of the instrument compared to a conventional high-resolving power spectrograph. The custom built injection fiber system with 3D-printed micro-lenses on top of it for the replicable high-resolution exoplanet and asteroseismology spectrograph at Subaru in combination with extreme adaptive optics of SCExAO, proved its high efficiency in a lab environment, manifesting up to ~77% of the theoretical predicted performance

Modal noise mitigation for high-precision spectroscopy using a photonic reformatter

Recently, we demonstrated how an astrophotonic light reformatting device, based on a multicore fibre photonic lantern and a three-dimensional waveguide component, can be used to efficiently reformat the point spread function of a telescope to a diffraction-limited psuedo-slit [arXiv:1512.07309]. Here, we demonstrate how such a device can also efficiently mitigate modal noise -- a potential source of instability in high resolution multi-mode fibre-fed spectrographs). To investigate the modal noise performance of the photonic reformatter, we have used it to feed light into a bench-top near-infrared spectrograph (R {\approx} 9,500, {\lambda} {\approx} 1550 nm). One approach to quantifying the modal noise involved the use of broadband excitation light and a statistical analysis of how the overall measured spectrum was affected by variations in the input coupling conditions. This approach indicated that the photonic reformatter could reduce modal noise by a factor of six when compared to a multi-mode fibre with a similar number of guided modes. Another approach to quantifying the modal noise involved the use of multiple spectrally narrow lines, and an analysis of how the measured barycentres of these lines were affected by variations in the input coupling. Using this approach, the photonic reformatter was observed to suppress modal noise to the level necessary to obtain spectra with stability close to that observed when using a single mode fibre feed. These results demonstrate the potential of using photonic reformatters to enable efficient multi-mode spectrographs that operate at the diffraction limit and are free of modal noise, with potential applications including radial velocity measurements of M-dwarfs.Comment: 13 pages, 9 figures (including appendix

Out of Earth II National conference on earth buildings

SIGLEAvailable from British Library Document Supply Centre-DSC:6314.406747(II) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Dataset for "The Airy fibre: an optical fibre that guides light diffracted by a circular aperture"

data used in the preparation of the pape