3,116 research outputs found
Dataset for Evanescent field refractometry in planar optical fiber
No full textDataset supports:
Holmes, C., et al (2017). Evanescent field refractometry in planar optical fiber. Optics Letters.</span
Dataset for: Self-assembled axicon lens in integrated optical fiber
No full textData supporting the published paper: Holmes, C., & Smith, P. G. R. (2019). Self-assembled axicon lens in integrated optical fiber. Optics Letters, 44(14), 3506-3509. DOI: 10.1364/OL.44.003506
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Planar micromachined glass cantilevers utilising integrated Bragg Fabry-Perot cavities
No full textHere we demonstrate a glass cantilever based on a unique micromachining and etching approach, combined with UV written Bragg gratings. We shall also discuss the increase in sensitivity by using two Bragg gratings to form Fabry-Pérot cavity. Cantilevers are in ultra sensitive force sensors used in applications such as Atomic Force Microscopy, mass sensing and acoustic transducers
Integrated optical differential pressure transducers achieved using thin buckled silica membranes and direct UV written planar Bragg gratings
No full textDirect UV written differential pressure sensors have been fabricated in a silica-on-silicon platform. The reported components achieve physical sensitivity through actuating planar Bragg gratings defined within a thin (<40 µm) silica membrane. The optimised transducer exploits the condition of static membrane buckling to resolve both positive and negative pressure differentials, either side of the membrane. The fabricated device has demonstrated operation over a 202 kPa range with a 0.36 kPa resolution
Variable immune-driven natural selection in the attachment (G) glycoprotein of respiratory syncytial virus
No full textA maximum-likelihood analysis of selection pressures acting on the attachment (G) glycoprotein gene of respiratory syncytial virus (RSV) from humans (HRSV) and bovines (BRSV) is presented. Six positively selected sites were identified in both group A and group B of HRSV, although only one site was common between them, while no positively selected sites were detected in BRSV. All positively selected sites were located within the ectodomain of the G protein and showed some association with positions of immunoglobulin (Ig) epitopes and sites of O-glycosylation. These results suggest that immune (antibody)-driven natural selection is an important determinant of RSV evolution and that this selection pressure differs among strains. The passage histories of RSV strains were also shown to affect the distribution of positively selected sites, particularly in HRSV B, and should be considered whenever retrospective analysis of adaptive evolution is undertaken
Direct UV written planar devices for sensing and telecommunication applications
No full textThis thesis reports the development and potential applications of several direct UV written devices. The material platform of these devices is a silica-on-silicon composite, fabricated using flame hydrolysis deposition.The device development within this thesis considers wet etching, micromachining and sputtering processes to enhance the physical and chemical actuation of direct UV written planar Bragg gratings. Physical actuation has been investigated through thermo-optic and strain-optic means, chemical actuation has been achieved through evanescent field exposure. Combining the chemical and physical actuators developed, a monolithic lab-on-a-chip based device has been fabricated. The demonstrated chip has the ability to monitor pressure, flow, temperature and refractive index of a measurand, flowing through a microfluidic channel.A novel multimode interference (MMI) based device is also presented, which uses an adaptive Bragg period to define the side walls of the device. The reported structure shows a potential reduction in excess loss, compared to alternative raster scanned device geometries for power splitting operations
Integrated corner mirrors physically micromachined in silica-on-silica
No full textIn integrated photonics, compact redirection of light can be achieved by corner (turning) mirrors, providing a route to higher density optical components. Corner mirrors have been demonstrated in both silicon-on-insulator and hollow waveguides with reported losses of 0.9dB [1] and 0.8dB [2] respectively. We report a novel method of fabricating mirrors on a silica-on-silicon substrate. The method utilises the complementary techniques of physical micromachining and direct UV writing, both providing rapid prototyping outside the cleanroom environment
Dataset for: Bend Monitoring and Refractive Index Sensing using Flat Fibre and Multicore Bragg gratings
No full textDataset supports: Holmes, C. et al (2020). "Bend Monitoring and Refractive Index Sensing using Flat Fibre and Multicore Bragg gratings". Measurement Science and Technology.</span
Integrated optic glass microcantilever with Bragg gratings forming a Fabry-Pérot interferometer for force sensing
No full textMicrocantilevers are the workhorse for ultra sensitive force sensors and are used in applications such as atomic force microscopy, sensing forces as small as 10pN [1]. In previous work [2] we have demonstrated the first integrated optical glass microcantilever, and we now show for the first time Bragg gratings forming a Fabry-Pérot interferometer acting to increase the force-sensitivity of the device. The fabrication of the glass microcantilever is based on a novel physical micromachining and etching approach, combined with UV written Bragg gratings. The advantages of the in-situ Fabry-Pérot interferometer will also be discussed
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