TECHNOLOGY - AIR GUIDING FIBERS
A special class of PBG guiding fibers is the air-guiding fibers, where the field is confined to an air-filled core. Like other PBG fibers, air-core fibers only guide light in a limited spectral region. For fibers guiding around 1550nm, a typical bandwidth is ~200nm. Outside this region, the fiber core is anti-guiding.
Guiding light in a hollow core holds many promising applications like high
power delivery without the risk of fiber damage, gas sensors or extreme low
loss guidance in vacuum.
Furthermore, this class of fiber has other spectacular properties not found
in any other fiber type. They are almost insensitive to bending (even at very
small bending radii) and extreme dispersion properties, such as anomalous
dispersion values in the thousands of ps/nm/km regime is easily obtained.
Due to a negligible contribution from the core material (air), the total dispersion
of PBG fibers is to a high degree dominated by waveguide dispersion.
