Light propagation in optical fibers is accompanied by random omnidirectional scattering. The small fraction of coherent guided light that escapes outside the cladding of the fiber forms a speckle pattern. Here, visual information imaged into the input facet of a multimode fiber with a transparent buffer is retrieved, using a convolutional neural network, from the side-scattered light at several locations along the fiber. This demonstration can promote the development of distributed optical imaging systems and optical links interfaced via the sides of the fiber.
The vast majority of medical endoscopes used today are based on optical fibers. Although most endoscopes are used to retrieve the image of the object at the distal end of the fiber endoscope, recent developments enable imaging the surrounding of the endoscope, such as swallowable tethered capsules. However, these capsules are much thicker than the optical fiber itself, and require mechanical rotations in order to scan the surrounding of the capsule. Hence, the ability to image the surrounding of a standard single-core fiber will be a major improvement to the current capabilities since it will allow for a much more convenient and possibly faster operation of the device, and will enable reaching places that are unreachable using the currently available technology. A mechanism that may enable such ability is the Rayleigh scattering that is present in standard optical fibers, and causes scattering of light that propagates inside the fiber in all directions. In this work we discuss two tasks we have recently investigated towards imaging the surrounding of a standard step-index multi-mode fiber. The first one is retrieving visual data that was input to the fiber based on Rayleigh side-scattered light using deep learning. The second one is focusing of Rayleigh side-scattered light using wave-front shaping, which is a possible means to overcome the very low intensity of Rayleigh scattering.
The optical Archimedes screw is a structured beam of light shown to be useful in conveying airborne particles. Such beams were demonstrated propagating along straight and curved trajectories. Here we demonstrate an optical Archimedes screw where both its linear and angular momenta are accelerating- allowing to both control its trajectory and transverse profile during propagation.
We demonstrate machine-learning assisted dynamic tracking of the shape of a multimode fiber whose spatial configuration is manipulated by the movement of three linear stages. The data source used for the analysis is the coherent speckle pattern of light that has made a round trip in the fiber.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.