Low-loss compact waveguiding with te modes in metal/dielectric waveguides for planar lightwave circuit / Mohd Zulkifli Chik

A waveguide is a structure which guides waves, such as electromagnetic waves or sound waves. There are different types of waveguide for each type of wave. The original and most common meaning is a hollow conductive metal pipe used to carry high frequency radio waves, particularly microwaves. Waveguides differ in their geometry which can confine energy in one dimension such as in slab waveguides or two dimensions as in fiber or channel waveguides. In addition, different waveguides are needed to guide different frequencies: an optical fiber guiding light (high frequency) will not guide microwaves (which have a much lower frequency). In this thesis, we investigate the effect of the metal to the wave propagation. We used effective index method to compute the effective indices and loss of the metal cladding waveguide. We design the structure with core silicon which has refractive index (3.5), the cladding was silica with refractive index (1.530) and the metal that was used is silver with refractive index (0.399) with permittivity. In the metal/dielectric waveguide structure, we investigated the effect of cladding width of the modes effective index and propagation loss and compared with waveguide structure without metal. Both these properties were investigated over the telecommunication wavelength 1.53 um to 1.61 um. The result obtained using effective index method shows that the cladding width influences the effective index and mode loss. When the cladding width is larger the losses exhibited by the modes in the waveguide decreases and as for the effective index computed, the value would increase as the cladding width is increased until it converge to a certain maximum value. All these result are consistent with publish result.