Minimally invasive optical systems allow to access deep tissue regions living organisms, for instance for microscopy or cell manipulation. Multi core fibers (CFB) are predestined for advancing needle-size microendoscopy, since they offer several 10,000 independent channels with a total outer diameter down to 0.2 mm. The applicability of CFBs as a means for undisturbed light transfer in optical systems is limited however, since random, unknown and time dependent phase distortions occurs between individual cores. This phase distortion is particularly susceptible to bending and needs to be calibrated in-vivo and without optical access to the distal side. Earlier we reported on a solution based on an in-situ phase calibration using virtual guide stars. To correct the phase distortion, we use a LCoS-based phase modulator (SLM) which simultaneously transforms the CFB into a phased array to generate arbitrary light patterns. We use this technique for endoscopic 3D raster scanning fluorescence microscopy. The scanning process is aided by a galvo mirror and a tunable lens to increase the speed to one Mega voxel (200x200x25) per second. Besides the possibility for imaging as an endoscope the technology can serve also applications like optical stretching, high precision cell ablation and single cell addressing in optogenetics. While precise cell rotation can allow tomographic refractive index reconstruction for instance in cancer diagnostics, the combination with CFBs can enable a translation to in-vivo or lab on a chip application. We demonstrate 2-axis cell rotation with a two-sided optical stretcher and rotation of non-Gaussian mode fields.
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