Rigorous analysis of acoustic modes in low and high index contrast silica fibers.

The vector acoustic modes in both well-established and emerging designs of optical waveguides have been studied through use of a computer code which has been developed based on the finite element method (FEM). Dispersion curves and the displacement vectors for the transverse and longitudinal acoustic modes and the modal hybridness have been determined and these are shown for both low and high index contrast silica (SiO2) acoustic waveguides. Stimulated Brillouin scattering (SBS) frequencies are also reported for the subwavelength size SiO2 optical waveguides.

Rigorous characterization of acoustic-optical interactions in silicon slot waveguides by full-vectorial finite element method.

For the first time detailed interactions between optical and acoustic modes in a silicon slot waveguide are presented. A new computer code has been developed by using a full-vectorial formulation to study the acoustic modes in optical waveguides. The results have shown that the acoustic modes in an optical slot waveguide are not purely longitudinal or transverse but fully hybrid in nature. The model allows the effects of Stimulated Brillouin Scattering and the associated frequency shift due to the interaction of these hybrid acoustic modes with the fully hybrid optical mode also to be presented.

Rigorous modal analysis of silicon strip nanoscale waveguides.

A full-vectorial H-field Finite Element Method has been used for the rigorous modal analysis of silicon strip waveguides. The spatial variation of the full-vectorial H and E-fields are also discussed in details and further, the Poynting vector is also presented. The modal area, hybridness, single mode operation and birefringence are also described for such silicon strip waveguides.

Characterization of silicon nanowire by use of full-vectorial finite element method.

We have carried out a rigorous H-field-based full-vectorial modal analysis and used it to characterize, more accurately, the abrupt dielectric discontinuity of a high index contrast optical waveguide. The full-vectorial H and E fields and the Poynting vector profiles are described in detail. It has been shown through this work that the mode profile of a circular silicon nanowire is not circular and also contains a strong axial field component. The single-mode operation, vector field profiles, modal hybridness, modal ellipticity, and group velocity dispersion of this silicon nanowire are also presented.

Numerical analysis of bent waveguides: bending loss, transmission loss, mode coupling, and polarization coupling.

A rigorous, full-vectorial and computationally efficient finite-element-based modal solution, together with junction analysis and beam propagation approaches have been used to study bending loss, transition loss, mode coupling, and polarization coupling in bent optical waveguides. The waveguide offset and their widths have been optimized to reduce the transition loss and the mode beating.