{"id":{"repo_id":"dundee","oai_identifier":"oai:discovery.dundee.ac.uk:studenttheses/c6ec5e01-199a-4caf-a154-a51633706ed2"},"canonical_url":"https://search.dev.ndltd.org/etd/dundee/oai:discovery.dundee.ac.uk:studenttheses/c6ec5e01-199a-4caf-a154-a51633706ed2","repository":{"repo_id":"dundee","name":"University of Dundee","base_url":"https://discovery.dundee.ac.uk/ws/oai"},"display":{"title":"Advanced fibre-based endoscopy for biophotonics applications","abstract":"Despite the tremendous advances witnessed in light microscopy over the past two decades, non-invasive optical imaging is still limited to penetration depths smaller than 1 mm into tissue. Multiple scattering caused by the refractive index inhomogeneities of biological matter rapidly distort any optical wavefront prop-agating through, rendering tissues opaque. Such turbidity restricts imaging, as well as other biophotonics techniques, to the most superficial layers of tissue.<br/><br/>A perspective strategy to overcome the turbidity of living matter exploits holographic light control in multimode optical fibres. This allows devising min-imally invasive imaging probes with footprints far bellow those of conventional endoscopes, as well as enhanced spatial resolution up to the diffraction limit de-termined by the numerical aperture (NA) of the fibre.<br/><br/>In this Thesis, high-resolution focussing is demonstrated with unprecedented ability across novel specialty fibres offering very-high NAs, by devising a system and methodologies which allow counteracting the severe mode-dependent loss affecting such fibres. The high quality and NA of the generated foci is capable of 3D optical confinement of dielectric microparticles, thus enabling the deliv-ery of holographic optical tweezers introduced through a bare optical fibre with cross-section comparable to a single cell. The holographic methods developed allow the manipulation of complex 3D arrangements of particles, as well as their independent positioning with nanometre-scale precision in all three dimensions.<br/><br/>Separately, a multimode fibre based deep-brain fluorescence imaging is demonstrated in animal models in vivo, allowing the identification of neuronal structures at depths exceeding 2 mm and resolving fine details down to ≈1 µm resolution.","abstract_html":"Despite the tremendous advances witnessed in light microscopy over the past two decades, non-invasive optical imaging is still limited to penetration depths smaller than 1 mm into tissue. Multiple scattering caused by the refractive index inhomogeneities of biological matter rapidly distort any optical wavefront prop-agating through, rendering tissues opaque. Such turbidity restricts imaging, as well as other biophotonics techniques, to the most superficial layers of tissue.&lt;br/&gt;&lt;br/&gt;A perspective strategy to overcome the turbidity of living matter exploits holographic light control in multimode optical fibres. This allows devising min-imally invasive imaging probes with footprints far bellow those of conventional endoscopes, as well as enhanced spatial resolution up to the diffraction limit de-termined by the numerical aperture (NA) of the fibre.&lt;br/&gt;&lt;br/&gt;In this Thesis, high-resolution focussing is demonstrated with unprecedented ability across novel specialty fibres offering very-high NAs, by devising a system and methodologies which allow counteracting the severe mode-dependent loss affecting such fibres. The high quality and NA of the generated foci is capable of 3D optical confinement of dielectric microparticles, thus enabling the deliv-ery of holographic optical tweezers introduced through a bare optical fibre with cross-section comparable to a single cell. The holographic methods developed allow the manipulation of complex 3D arrangements of particles, as well as their independent positioning with nanometre-scale precision in all three dimensions.&lt;br/&gt;&lt;br/&gt;Separately, a multimode fibre based deep-brain fluorescence imaging is demonstrated in animal models in vivo, allowing the identification of neuronal structures at depths exceeding 2 mm and resolving fine details down to ≈1 µm resolution.","abstract_has_math":false,"creators":["Oliveira Teixeira Leite, Ivo Jorge"],"institution":"University of Dundee","degree_name":"Doctor of Philosophy","degree_level":"Doctoral Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Cuschieri, Alfred","Cizmar, Tomas"],"committee_chairs":[],"committee_members":[],"year":2018,"date_issued":"2018","date_published":"2018","updated_at":"2026-07-24T02:08:39Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:discovery.dundee.ac.uk:studenttheses/c6ec5e01-199a-4caf-a154-a51633706ed2"],"render_values":[{"text":"oai:discovery.dundee.ac.uk:studenttheses/c6ec5e01-199a-4caf-a154-a51633706ed2","href":null,"code":true}]}]},"links":{"outbound_url":"https://discovery.dundee.ac.uk/en/studentTheses/c6ec5e01-199a-4caf-a154-a51633706ed2","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Cuschieri, Alfred","Cizmar, Tomas"]},{"key":"dc:creator","label":"Author","values":["Oliveira Teixeira Leite, Ivo Jorge"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2018"]},{"key":"dc:date.issued","label":"Date","values":["2018"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Physics"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Dundee"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://discovery.dundee.ac.uk/en/studentTheses/c6ec5e01-199a-4caf-a154-a51633706ed2"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral Thesis"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights.embargodate","label":"Dc Rights Embargodate","values":["2019-01-31"]},{"key":"dc:rights.embargoreason","label":"Dc Rights Embargoreason","values":["/dk/atira/pure/core/document/studentthesisembargoreason/commercialexploitation"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:discovery.dundee.ac.uk:studenttheses/c6ec5e01-199a-4caf-a154-a51633706ed2","https://discovery.dundee.ac.uk/en/studentTheses/c6ec5e01-199a-4caf-a154-a51633706ed2"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://discovery.dundee.ac.uk/files/29105772/Thesis_IvoLeite.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Despite the tremendous advances witnessed in light microscopy over the past two decades, non-invasive optical imaging is still limited to penetration depths smaller than 1 mm into tissue. 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The high quality and NA of the generated foci is capable of 3D optical confinement of dielectric microparticles, thus enabling the deliv-ery of holographic optical tweezers introduced through a bare optical fibre with cross-section comparable to a single cell. The holographic methods developed allow the manipulation of complex 3D arrangements of particles, as well as their independent positioning with nanometre-scale precision in all three dimensions.<br/><br/>Separately, a multimode fibre based deep-brain fluorescence imaging is demonstrated in animal models in vivo, allowing the identification of neuronal structures at depths exceeding 2 mm and resolving fine details down to ≈1 µm resolution."]},{"key":"dc:title","label":"Title","values":["Advanced fibre-based endoscopy for biophotonics applications"]}]}],"canonical_facts":{"dc:contributor.advisor":["Cuschieri, Alfred","Cizmar, Tomas"],"dc:creator":["Oliveira Teixeira Leite, Ivo Jorge"],"dc:date":["2018"],"dc:date.issued":["2018"],"dc:description.abstract":["Despite the tremendous advances witnessed in light microscopy over the past two decades, non-invasive optical imaging is still limited to penetration depths smaller than 1 mm into tissue. 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