Light Transmission Through a Hollow Core Fiber Bundle

This paper reports on the fabrication and performance of a fiber bundle with seven hollow cores arranged in a hexagonal pattern. The bundle shows individual core transmission with less than 0.07% core-to-core coupling over a length of 11 cm. Each core exhibits several transmission windows in the visible to near infrared region. These low attenuation regions with large higher order mode suppression are a result of anti-resonant guidance due to the negative curvature membranes encircling the cores. The central core exhibits the widest transmission window with a minimum loss of 4 dB/m between 1250 nm and 1450 nm. The lowest loss for the central core is estimated to be 2.5 dB/m at 600 nm. Such hollow core fiber bundles may be employed in applications including communication, imaging systems, high power laser delivery, or sensing.