3D imaging through a single optical fiber

Endoscopes and similar instruments use bundles of optical fibers to relay each pixel of an image from facet to facet. But even one of these multi-mode fibers supports enough modes to relay a complete image, the problem being that modal dispersion results in the image being scrambled. However, by treating the fiber as a complex aberration and applying corrective beam shaping it is possible to relay an image along the fiber length. Here we show that by beam-shaping of a pulsed laser we can produce a scanning spot at the distil end of the fiber and by measuring the time dependent intensity of the back-scattered light we can achieve 3D imaging. We demonstrate imaging up to 3m from the fiber with a lateral resolution of 60x60 pixels and a millimetric depth resolution. Such minimally invasive endoscopic 3D imaging has applications in healthcare and remote inspection.

Automated summary

Endoscopes and similar instruments use bundles of optical fibers to relay each pixel of an image. However, modal dispersion can scramble the image. By treating the fiber as a complex aberration and applying corrective beam shaping, an image can be relayed along the fiber length. By beam-shaping a pulsed laser, a scanning spot can be produced at the distil end of the fiber, and 3D imaging can be achieved by measuring the time dependent intensity of the back-scattered light.