Simulation And Fabrication Of Optical Waveguide Devices In Silicon-on-Insulator

Optical fiber communication is based on opto-electronic technology. On the one hand, the realization of its dense opto-electro-opto conversion benefits from the cheap and mature integrated circuit technology, and the other, the electronic bottleneck limits the communication capability to far less than the fiber can load. Just like the development of microelectronic technology, the goal of the opto-electronic or photonic technology is integration. This kind of integration is called as optical integration. There are two directions of the optical integration: one is function integration, and the other is amount integration. The two ways of integration are opto-opto and opto-electronic integration. The two integration methods are single-chip and hybrid integration. Silicon is an important kind of material. At first, the transparent frequency window of silicon is same with the optical fiber. Secondly, the optical integration needs the powerful, low-cost and mature micro-manufacturing technology for silicon. Thirdly, plasma effect in silicon makes it possible to realize optical modulator or switch. Fourthly, the maturation of silicon-on-insulator (SOI) wafer forming technology broaden the application area of silicon in optical integration, such as for photonic devices (silicon wire, microring resonator), photonic crystal devices etc.This paper focused on the design and fabrication of optical and opto-electronic devices on SOI wafer. The finite element method is an important numerical method to solve the modes of optical waveguie. When the conventional nodal element is used to solve the full vector Helmoholtz equation, the spurious modes appear. The penalty term is added to the respecting functional and the spurious modes are suppressed out of the interesting area. But defining an appropriate penalty factor is difficult and based on experiences. This paper gave another kind of penalty term, which could improve the mode fields and eigenvalues. The solution efficiency was also enhanced. The physical background of this penalty term was analyzed. The nodal element destines the spurious modes in full Helmholtz equation. This problem is solved inside and out when the vector element is applied in the finite element method. The Matlab program to realize this numerical method was written. The perfect matched layers (PMLs) were also introduced in the numerical model of SOI rib waveguide. The eigenvalues in this numerical method were compared with the ones from the effective index method. The loss relation of leaking to substrate with the buried oxide (BOX) thickness for silicon wire was calculated, and its leaking field was also analyzed.The Y-branch and 3-branch of SOI photonic crystal were calculated by the two-dimension scalar finite element method in in-plane TE and TM polarization. The power transmission spectra were obtained. This method was also applied to calculate the response spectra of microring resonator. The symbol toolbox of Matlab helped to analyze the response spectra of reflection-assisted microring resonator. Its best response conditions of different ports were achieved.