Thesis of Fatima El Moussawi

Defense of thesis  Fatima El Moussawi - laboratory PhLAM

Specialty optical fiber for ultra-miniaturized biomedical endoscopes

Abstract :

The lens-less endoscope is a promising ultra-miniaturized imaging tool with the potential to enable minimally invasive and cellular-level resolution in-vivo imaging deep inside biological tissue. The main idea of the lens-less endoscope is a device capable of being fixed on the head of a small animal containing only an optical waveguide capable of collecting light, retaining its information content, and transporting it fiber-optically to remote optics and opto-electronics. The interest of this miniaturized endoscope stems from its ability to allow new functionalities because light source and detectors are remote as well as the light weight and flexibility of the optical fibers that constitute here the main part of the imaging system. We present in this thesis a novel fiber-optic component, a “tapered multi-core fiber”, designed for integration into ultra-miniaturized endoscopes for minimally invasive two-photon point-scanning imaging and to address the power delivery issue that has faced multi-core fiber-based lensless endoscopes. We report the design, fabrication, and application of the tapered multi-core fiber, where we were able to perform two-photon imaging of fluorescent samples in both forward and backward directions. Our results show that tailoring of the taper profile of the multi-core fiber brings new degrees of freedom that can be efficiently exploited for lensless endoscopes.

Keywords : endoscopes,fibre optique,ultra miniaturisé,Matrice de transmission