Modelling optical waveguide bends and applications to plasmon-polariton waveguides

Optical waveguide bends are key building blocks in many integrated optical components. Accurate numerical modelling of these bends is of great practical value to the design of the integrated optical technology. Analyzed in this thesis are the propagation characteristics of optical waveguide bends based on the method of lines (MoL), not only for its good numerical performances (accuracy, speed of computation and minimal memory requirements), but also for its high suitability for the analysis of waveguide structures.;This thesis gives the detailed formulation for the calculation of the waveguide-bending radiation loss and the transition loss due to modal mismatch at the junctions. Besides, the 1D and 2D spatial field distribution algorithms are also covered in the formulation.;The code based on the formulation has been implemented successfully. To validate the code, we applied it to three typical waveguide structures appearing in other literatures and compared the results. The comparison shows that our code works very well, and can be used not only for the lossless dielectric media, but also for the lossy media at the optical frequency.;This thesis also explores the application of the developed code to metal waveguide bends. The numerical results of the propagation characteristics of the metal waveguide bends at the optical frequencies are presented for what is believed to be the first time.