Browsing NTNU Open by Author "Gibson, Ursula"
Now showing items 1-20 of 70
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A review of materials engineering in silicon-based optical fibre
Healy, Noel; Gibson, Ursula; Peacock, Anna (Journal article; Peer reviewed, 2017)Semiconductor optical fibre technologies have grown rapidly in the last decade and there are now a range of production and post-processing techniques that allow for a vast degree of control over the core material's ... -
Alkaline oxide interface modifiers for silicon fiber production
Nordstrand, Erlend Fjøsne; Dibbs, Andrew; Eraker, Andreas Juvkam; Gibson, Ursula (Journal article; Peer reviewed, 2013)We demonstrate the ability to pull small diameter silicon-core fibers with low oxygen content by using interface modifiers between the silica cladding and the semiconductor. Alkali earths scavenge oxygen and form a ... -
All-fibre heterogeneously-integrated frequency comb generation using silicon core fibre
Sohanpal, Ronit; Ren, Haonan; Deakin, Callum; Heidt, Alexander; Hawkins, Thomas A.; Ballato, John; Gibson, Ursula; Peacock, Anna; Liu, Zhixin (Peer reviewed; Journal article, 2022)Originally developed for metrology, optical frequency combs are becoming increasingly pervasive in a wider range of research topics including optical communications, spectroscopy, and radio or microwave signal processing. ... -
All-optical high-speed modulation of THz transmission through silicon core optical fibers
Sørgård, Trygve Reinertsen; Hawkins, Thomas; Ballato, John; Österberg, Ulf Lennart; Gibson, Ursula (Journal article; Peer reviewed, 2021)High speed optical modulation of THz radiation is of interest for information processing and communications applications. In this paper infrared femtosecond pulses are used to generate free carriers that reduce the THz ... -
Band-edge modification and mid-infrared absorption of co-deposited FexZn1-xS thin films
Molland, Nelly-Ann; Ghadyani, Zahra; Karhu, Eric Andrew; Poggio, Stefano; Nematollahi, Mohammadreza; Kildemo, Morten; Reenaas, Turid Worren; BelBruno, Joseph; Gibson, Ursula (Journal article; Peer reviewed, 2015)The bandgap of iron-doped ZnS has been reported by others to change significantly under the addition of a few atomic percent of iron, which would have significant implications for solar energy. Here, thin films of FexZn1-xS ... -
Broadband infrared and THz transmitting silicon core optical fiber
Sørgård, Trygve; Song, Seunghan; Vullum, Per Erik; Kores, Cristine; Mølster, Kjell Martin; Laurell, Fredrik; Hawkins, Thomas A.; Ballato, John; Österberg, Ulf Lennart; Gibson, Ursula (Peer reviewed; Journal article, 2020)Silicon waveguide structures are a viable alternative for the transmission of signals over a wide range of frequencies, and new fabrication methods are key to increased applications. In this work, THz transparency of ... -
Bulk fabrication and properties of solar grade silicon microwires
Martinsen, Fredrik A; Ballato, John; Hawkins, Thomas A.; Gibson, Ursula (Journal article; Peer reviewed, 2014)We demonstrate a substrate-free novel route for fabrication of solar grade silicon microwires for photovoltaic applications. The microwires are fabricated from low purity starting material via a bulk molten-core fibre ... -
Characterisation of Silicon (Si) fibre Bragg grating in near-infrared band for strain and temperature sensing
Theodosiou, Antreas; Kalli, Kyriacos; Hawkins, Thomas A.; Ballato, John; Fokine, Michael; Gibson, Ursula (Journal article; Peer reviewed, 2018)This letter describes fibre Bragg grating inscription in crystalline siliconcore fibre using visible light femtosecond laser pulses. The femtosecond pulses at 517 nm propagate through the transparent silica glass cladding ... -
Characterization of electrical activity and lifetime in compensated multicrystalline silicon
Austad, Karianne (Master thesis, 2011)This master's thesis concerns the electrical activity and lifetime in compensated multicrystalline silicon wafers used for solar cell production.Resistivity profiles across grain boundaries have been obtained by a Four ... -
Characterization of GaN:ZnO p-n junctions
Knutsen, Hege (Master thesis, 2011)In this master thesis, thin lms of ZnO doped with various cobalt concentra-tions have been grown using Pulsed Laser Deposition (PLD). This growthtechnique is preferred because it is able to grow thin lms from a targetmaterial ... -
Characterization of ZnS:Cr films for Intermediate Band Solar Cells
Aamodt, Tor Ingve (Master thesis, 2011)In this thesis samples of ZnS:Cr thin films have been made through physicalvapor deposition (PVD) with resistive heating and characterized by severalmethods. The thin films are of various thicknesses and contain ... -
CO2 laser annealed SiGe core optical fibers with radial Ge concentration gradients
Wu, Wei; Balci, Mustafa H.; Song, Seunghan; liu, chunxin; Fokine, Michael; Laurell, Fredrik; Hawkins, Thomas A.; Ballato, John; Gibson, Ursula (Peer reviewed; Journal article, 2020)CO2 laser annealing of SiGe core, glass-clad optical fibers is a powerful technique for the production of single-crystal cores with spatially varying Ge concentrations. Laser power, laser scan speed and cooling air flow ... -
Compositional and structural properties of pulsed laser-deposited ZnS:Cr films
Nematollahi, Mohammadreza; Yang, Xiaodong; Seim, Eivind; Vullum, Per Erik; Holmestad, Randi; Gibson, Ursula; Reenaas, Turid Worren (Journal article; Peer reviewed, 2016)We present the properties of Cr-doped zinc sulfide (ZnS:Cr) films deposited on Si(100) by pulsed laser deposition. The films are studied for solar cell applications, and to obtain a high absorption, a high Cr content ... -
Compositional Characterisation of Optical InGaSb-core Microfibres
Svendsen, Silje Katrine (Master thesis, 2017)This thesis constitutes the first step on the way to understanding and applying the ternary InGaSb-semiconductor alloy in the field of nonlinear fibre optics. This semiconductor material is also interesting for applications ... -
Continuous-wave Raman amplification in silicon core fibers pumped in the telecom band
Huang, Meng; Sun, Shiyu; Wu, Dong; Ren, Haonan; Shen, Li; Hawkins, Thomas; Ballato, John; Gibson, Ursula; Peacock, Anna C. (Peer reviewed; Journal article, 2021)Stimulated Raman amplification is observed for the first time in the silicon core fiber (SCF) platform. The SCFs were tapered to obtain sub-micrometer core dimensions and low optical transmission losses, facilitating ... -
Core opportunities for future optical fibers
Ballato, John; Gibson, Ursula (Journal article; Peer reviewed, 2021) -
Crystalline GaSb-core optical fibers with room-temperature photoluminescence
Song, Seunghan; Healy, Noel; Svendsen, Silje; Österberg, Ulf; Cuervo Covian, Alejandra; Liu, Jifeng; Peacock, Anna; Ballato, John; Laurell, Fredrik; Fokine, Michael; Gibson, Ursula (Journal article; Peer reviewed, 2018)Glass-clad, GaSb-core fibers were drawn and subsequently laser annealed. The asdrawn fibers were found to be polycrystalline, possess Sb inclusions, and have oxide contamination concentrations of less than 3 at%. Melting ... -
Design and Analysis of Optical Fiber Probes for Glucose Sensing in the Peritoneal Cavity
Walmsness, Per Magnus (Master thesis, 2016)This thesis is focused on the design and analysis of optical fiber probes for glucose sensing in the peritoneal cavity. The probes are to be used as absorption cells for near-infrared absorption spectroscopy of peritoneal ... -
Doped ZnS Thin Films for Intermediate Band Solar Cells - Deposition and Characterization
Hope, Benjamin Roaldssønn (Master thesis, 2015)Intermediate band solar cells (IBSCs) has the potential of increasing the efficiency and reducing the cost of commercial solar cells. The realization of such cells relies on the development of intermediate band (IB) ... -
Effect of Germanium in Silicon for Solar Applications
De Martino, Giuseppe (Master thesis, 2016)The effect of Ge in multicrystalline Silicon wafers is studied along with a comparison in smaller scale systems (microwires).