Multiplexed light source for flexible coupling into fan-out fiber bundles in biomedical optical imaging

Multimodal endoscopic imaging enables robust intraoperative tissue differentiation. Different modalities, such as hyper- or multispectral imaging, spatial frequency domain imaging, fringe projection elastography, or fluorescence-based methods, pose different illumination requirements. Fan-out fiber bundles combined with 3D-printed microoptics offer a flexible solution for multimodal illumination by using each core for one modality at a time while being easily integrable into the working channel of surgical endoscopes. However, due to the varying and sometimes overlapping requirements of each modality, options to couple many different light sources into every core are not readily available. This work presents two flexible coupling setups using incoherent and coherent sources. The setups consist of dichroic filters to combine the optical paths of each source and a rotatable mirror to control the coupling into each cores. Both systems are characterized and tested on tissue-mimicking silicone phantoms to simulate tissue differentiation using different modalities. The systems show negligible chromatic aberrations while providing high output powers, which results in robust differentiation. 20 dizinische Anwendungen T Alexander Brielke