A practical hollow-core photonic crystal fiber design suitable for attaining low-loss propagation is analyzed. The geometry involves a number of localized elliptical features positioned on the glass ring that surrounds the air core and separates the core and cladding regions. The size of each feature is tuned so that the composite core-surround geometry is antiresonant within the cladding band ...

We have fabricated microstructured polymer optical fibers that guide light in a hollow core using the photonic bandgap mechanism. The hollow core allows the use of polymer fibers to be extended to wavelength ranges where material absorption typically prohibits their use, with attenuation lower than the material loss observed in the infrared. The fabrication method is similar to other microstruc...

in this paper, finite element elastic contact analysis of a functionally graded (fg) hollow brake disk in contact with pad, subjected to rotation, contact pressure and frictional heat is presented. the material properties vary through the thickness according to a power-law characterised by a grading index, n. the material property is purely steel at the core part and gradually moves and approac...