Fundamental Research Of SOI Optical Waveguide And Optical Splitter

The growth of communication with new service and increasing subscribers requires increasing data rates and channels. Optical splitter is one of the key devices in integrated optics. They are usually applied to optical signal distribution systems. Such as cable television , broadcasting systems and PON systems . In this thesis, Y-branch and multimode interference in SOI technology are studied and simulated.The SOI single mode wave-guide with large cross-section can be realized by rib structure. The single mode condition for SOI wave-guide is obtained by the numerical method of effective index method (EIM).Y-branch has a simple structure and high reproducibility, it is possible to fabricate compact branching devices with stable branching rations. We propose a novel and simple Y-branch configuration with SIMOX SOI wafers in order to achieve an asymmetric branching ration and low excess loss. The proposed structure only deviate the center axes of input taper wave-guides. Using the beam propagation method (BPM) simulation, we confirm that wide controllability of the branching ratio and low excess loss can be realized by this structure. We also describe 1 X 2 Y-branch splitters with an asymmetric branching ratio from 50 to 94%.Multimode interference (MMI) couplers based on the self-imaging effect are rapidly getting popular because of the advantage of low loss, compact size and large fabrication tolerance .The thesis studied the principle of the MMI coupler .The optical field distribution in the multimode wave-guide is modeled by EIM and mode propagation analysis method (MPA). we present the design and simulation of an integrated 1 X 2,1 X 4 SI-MMI ,2 X 2 PI-MMI splitters with SOI technology. The devices realized the function of the coupler and show uniform output.