CONTROLLED OPTICAL FOCUSING THROUGH FLEXIBLE GRADED-INDEX MULTIMODE FIBERS WITHOUT DISTAL END ACCESS

摘要

Methods, apparatus, and systems for focusing light and remote imaging through a multi-mode fiber without pre-calibration and without direct localized feedback from the distal end of the fiber. Focus control is performed by optimally shaping the wavefront input to the fiber's proximal end according to feedback information embedded in back- propagating fluorescence from the distal end, via processing that exploits the partial cylindrical symmetry of the fiber, and which optimizes according to a weighting mask. Also included is a method for efficient photo-bleaching of a fluorescently-tagged sample, which optimizes the speed and efficiency of the photo-bleaching while minimizing or avoiding damage to non-tagged areas of the sample.