HE11 mode in water-filled hollow core Bragg fiber with a gold layer and dispersive materials

A recent analytical method is used to determine the spectral and amplitude sensitivities for HE11 mode in a hollow core Bragg fiber with or without a gold layer when the dispersion relations for all layers are considered. The fiber without a gold layer is made by a water core, surrounded by periodic reflector layers of polystyrene and polymethyl methacrylate with high and low refractive indices, respectively. The thicknesses of the cladding layers are calculated by using the quarter wave condition for two assumed initial bandgap wavelengths (λ0 = 0.5 m and λ0 = 0.68 m). The optical confinement for the HE11 mode in the core, at the minimum-loss wavelength, is increased over four orders (104) of magnitude when a high index material just before the outermost region of a hollow core Bragg fiber is replaced with a gold layer with an optimized thickness. Also, the amplitude sensitivity at the minimum-loss wavelength is increased for an optimized thickness of the gold layer.