Research On Design And Analysis Technology Of The OXC Oriented MEMS Optical Switch

With the growing of global informationalization, the capacity of communication networks increases rapidly, The "optical to electronic to optical" switching mode of current optical fiber communication networks has become the "electronic bottleneck" of networks. All-optical network is the trend of communication networks and optical cross-connect (OXC) is the core of all-optical network. Being the key component of OXC, the optical switch is a hotspot in optical communication research field. Simultaneously, because of its many advantages, MEMS optical switch has become an important research field in micro-electro-mechanical system. For application in OXC, this dissertation presents a optical switch with self-positioning two-axis micro-mirror in free space and studies its designation, analysis technology and process implementation method. The main contents include the following.(1) The integrated design method for MEMS optical switchThis part describes the bottom-up and top-down integrated MEMS design method. With the help of the integrated MEMS design tools, the architecture of MEMS optical switch integrated design is discussed, the electro-mechanical model of the two-axis micro-mirror and the system macro-model of the optical switch is set up, so the foundation of system analysis is established.(2) Numerical simulation of the two-axis micro-mirror structureBy the theory of FEA(finite element analysis), the FE(finite element) model of two-axis micro-mirror is set up. Model-frequency analysis, spring constant analysis and dynamics analysis are carried out. With the couple-field analysis tools, the electrostatic-structure couple-field analysis is carried out under normal working conditions and the pull-in voltage and release voltage are also analyzed.(3) Micro-mirror optical features analysisBased on the operation mode of optical switch in OXC, the relation between the reflection, refraction, surface roughness parameters of the multilayer mirror and its optical features are discussed. With Gauss laser beam as the lamp-house, the light power and its intensity distribution on the mirror and in the fiber cross section are analyzed for different hole sizes and optical fiber heights. The optical switch insertion loss, return loss and crosstalk parameters are also calculated.(4) The process implementation for the optical switchOn the basis of investigation on current silicon micromachining processes, the process flows and layouts are designed for an available domestic two-layer polysilicon surface micromachining process. An improved structure of the optical switch and corresponding process flows and layouts are given out for a standard process, the three-layer polysilicon surface micromachining process, and so the design can be realized by the foundry service.