antireflection coatingsfinite difference methodsgeometrical opticsholey fibresoptical design techniquesphotonic crystalsporosityporous materialsrefractive indexterahertz wavesbending radiuseffective mode areafull vectorial finite difference methodmetal-coated central holemode effective indexoptical attenuationporosityporous octagonal photonic crystal fibre designstructure geometrical parameter effectsterahertz applications
2015