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Fabrication et applications de structures 3D submicrométriques par écriture laser direct utilisant l'absorption à un photon
le 19 janvier 2015
A 10h00 dans l'auditorium Chemla de l'Institut d'Alembert
Mai-Trang DO
This work deals with a novel microscopy technique based on the ultra-low one-photon absorption (LOPA) mechanism of photosensitive materials for fabrication of arbitrary two- and three-dimensional (2D, 3D) submicrometer structures.
First, we theoretically investigated the intensity distribution at focusing region of a high numerical aperture objective lens as a function of various working conditions, such as propagation of light in an inhomogeneous and/or absorbing medium. We demonstrated that when working with refractive index mismatch-free and very low absorption conditions, the light could be focused deeply inside the material, allowing a 3D optical manipulation.
We then demonstrated experimentally the use of this simple technique for fabrication of desired structures. Different 2D and 3D structures, with a feature as small as 150 nm, have been created in SU8 photoresist by using a low power and continuous-wave laser emitting at 532 nm. Furthermore, we demonstrated that it is possible to fabricate a polymer-based photonic structure containing a single nanoparticle (NP), by using a double-step method. Indeed, the LOPA microscopy allowed us first to accurately determine the location of a single gold NP and then to embed it as desired into an arbitrary SU8 photonic structure. The coupling of a gold NP and a polymer-based photonic structure was theoretically and experimentally investigated showing a six-fold photons collection enhancement as compared to that of a NP in unpatterned film.
First, we theoretically investigated the intensity distribution at focusing region of a high numerical aperture objective lens as a function of various working conditions, such as propagation of light in an inhomogeneous and/or absorbing medium. We demonstrated that when working with refractive index mismatch-free and very low absorption conditions, the light could be focused deeply inside the material, allowing a 3D optical manipulation.
We then demonstrated experimentally the use of this simple technique for fabrication of desired structures. Different 2D and 3D structures, with a feature as small as 150 nm, have been created in SU8 photoresist by using a low power and continuous-wave laser emitting at 532 nm. Furthermore, we demonstrated that it is possible to fabricate a polymer-based photonic structure containing a single nanoparticle (NP), by using a double-step method. Indeed, the LOPA microscopy allowed us first to accurately determine the location of a single gold NP and then to embed it as desired into an arbitrary SU8 photonic structure. The coupling of a gold NP and a polymer-based photonic structure was theoretically and experimentally investigated showing a six-fold photons collection enhancement as compared to that of a NP in unpatterned film.
- Type :
- Séminaires - conférences, Thèses - HDR