TY - JOUR T1 - Exploiting modal demultiplexing properties of tapered optical fibers for tailored optogenetic stimulation JF - bioRxiv DO - 10.1101/199273 SP - 199273 AU - Marco Pisanello AU - Filippo Pisano AU - Leonardo Sileo AU - Emanuela Maglie AU - Elisa Bellistri AU - Barbara Spagnolo AU - Gil Mandelbaum AU - Bernardo L. Sabatini AU - Massimo De Vittorio AU - Ferruccio Pisanello Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/10/06/199273.abstract N2 - Optogenetic control of neural activity in deep brain regions requires precise and flexible light delivery with non-invasive devices. To this end, Tapered Optical Fibers (TFs) represent a minimally-invasive tool that can deliver light over either large brain volumes or spatially confined subregions. This work links the emission properties of TFs with the modal content injected into the fiber, finding that the maximum transversal propagation constant (kt) and the total number of guided modes sustained by the waveguide are key parameters for engineering the mode demultiplexing properties of TFs. Intrinsic features of the optical fiber (numerical aperture and core/cladding diameter) define the optically active segment of the taper (up to ∼3mm), along which a linear relation between the propagating set of kt values and the emission position exists. These site-selective light-delivery properties are preserved at multiple wavelengths, further extending the range of applications expected for tapered fibers for optical control of neural activity. ER -