Bend-resistant high-resolution imaging optical fiber

•A bend-resistant high-resolution imaging optical fiber comprising over five thousand cores was reported and characterized.•The fiber is made of low-cost commercial-available glasses and has high numerical aperture.•No degradation of imaging is demonstrated at a bending radius of less than 2 cm and at an extensive wavelength range. We report design, fabrication, and characterization of bend-resistant high-resolution imaging optical fiber comprising over five thousand cores. The fiber is made of low-cost commercial-available H-ZK9B and H-K3 glasses which gives rise to a maximum numerical aperture up to 0.552 at 750 nm wavelength. The multi-stacking arrays of three-sized cores can effectively suppress the core-to-core crosstalk and raise the bend resistance. No degradation of imaging is demonstrated at a bending radius less than 2 cm and at an extensive wavelength range from the visible to the near-infrared, showing a substantial improvement over commercial state-of-the-art fiber bundles.