title: Focusing and imaging with increased numerical apertures through multimode fibers with micro-fabricated optics.
abstract: The use of individual multimode optical fibers in endoscopy applications has the potential to provide highly miniaturized and noninvasive probes for microscopy and optical micromanipulation. A few different strategies have been proposed recently, but they all suffer from intrinsically low resolution related to the low numerical aperture of multimode fibers. Here, we show that two-photon polymerization allows for direct fabrication of micro-optics components on the fiber end, resulting in an increase of the numerical aperture to a value that is close to 1. Coupling light into the fiber through a spatial light modulator, we were able to optically scan a submicrometer spot (300 nm FWHM) over an extended region, facing the opposite fiber end. Fluorescence imaging with improved resolution is also demonstrated.
authors.forename: S
authors.initials: S
authors.lastname: Bianchi
authors.forename: V P
authors.initials: VP
authors.lastname: Rajamanickam
authors.forename: L
authors.initials: L
authors.lastname: Ferrara
authors.forename: E
authors.initials: E
authors.lastname: Di Fabrizio
authors.forename: C
authors.initials: C
authors.lastname: Liberale
authors.forename: R
authors.initials: R
authors.lastname: Di Leonardo
mesh_terms: D055616:Microtechnology / Q000295:instrumentation*; D055100:Optical Fibers; D061848:Optical Imaging / Q000295:instrumentation*; D017785:Photons; D011137:Polystyrenes / Q000737:chemistry
chemical_list: D011137:Polystyrenes