A microstructured fiber having a cladding comprising a number of elongated features
that are arranged to provide concentric circular or polygonial regions surrounding
the fiber core. The cladding comprises a plurality of concentric cladding regions,
at least some of which comprising cladding features. Cladding regions comprising
cladding features of a relatively low index type are arranged alternatingly with
cladding regions of a relatively high index type. The cladding features are arranged
in a non-periodic manner when viewed in a cross section of the fiber. The cladding
enables waveguidance by photonic bandgap effects in the fiber core. An optical
fiber of this type may be used for light guidance in hollow core fibers for high
power transmission. The special cladding structure may also provide strong positive
or negative dispersion of light guided through the fiber-making the fiber useful
for telecommunication applications.
