Controlling light in scattering media using ultrasound modulation
Light-based methods are fundamental in biology and biomedical sciences. They allow for non-invasive diagnosis and localized treatments with resolutions down to the sub-cellular level. However, light scattering inside biological tissue constrains the maximum depth at which current methods can operate...
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| Tipo de recurso: | tesis de maestría |
| Fecha de publicación: | 2022 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/377207 |
| Acceso en línea: | https://hdl.handle.net/2117/377207 |
| Access Level: | acceso abierto |
| Palabra clave: | Light -- Scattering Photonics ultrasound scattering optical microscopy laser surgery Llum -- Difusió Fotònica Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Telecomunicació òptica::Fotònica |
| Sumario: | Light-based methods are fundamental in biology and biomedical sciences. They allow for non-invasive diagnosis and localized treatments with resolutions down to the sub-cellular level. However, light scattering inside biological tissue constrains the maximum depth at which current methods can operate. In this work, we show that light can be focused and controlled in scattering media using ultrasound waves. We experimentally prove how ultrasound waves can work as embedded lenses in the scattering media, helping to compensate for scattering and redirect light toward a deeper focus. Our results demonstrate qualitatively and quantitatively how such ultrasound-enabled lenses enable up a factor of 7 improvement in light focusing for samples with a scattering coefficient of 3.5 1/mm, compared to traditional focusing with external elements. This allows to resolve images of test samples immersed in scattering media - USAF target with spacing of 27.8 um - that would be completely hidden with existing methods. |
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