Researchers have invented a new kind of air-filled optical fiber bundle that could significantly advance endoscopes used for medical procedures. The new technology might also lead to endoscopes that produce images using infrared wavelengths, which would allow diagnostic techniques that are not viable with endoscopes today.
Endoscopes use bundles of optical fibers to transmit images, from inside the body. Light falling on one end of the fiber bundle travels through each fiber to the far end, allowing an image to be carried in the form of thousands of spots that are much like the pixels that make up a digital picture.
Optical fibers consist of an inner core and an outer cladding with diverse optical properties, which traps the light inside and allows it to travel down the fiber. Instead of using cores and claddings made of two types of glass, like most fiber bundles, the new bundles use an array of glass cores enclosed by hollow glass capillaries, which are filled with air, that act as the cladding.
In The Optical Society (OSA) journal, researchers show that their new fiber bundles, which they call air-clad imaging fibers, sustain the resolution of the best commercial imaging fibers, at twice the wavelength range that the commercial fibers can be used. The new fiber could be used to create endoscopes that are smaller or have higher resolutions than those available today.