Based On The Design And Characteristics Of The Mzi Optical Waveguide Moems Pressure Sensors

Micro-Opto-Electro-Mechanical Systems (MOEMS) is an emerging discipline which refers to micro-optics, micro-mechanical and micro-electronics technology. Because the use of an integrated production process, it has the advantages of, small size, fast response, integrated positioning accuracy, large-scale production capacity and low-cost. MOEMS has become a hot research theories of science and technology.Several MOEMS structure of pressure sensors are discussed. According to MOEMS for the current direction of development, a MOEMS pressure sensor based on Mach-Zehnder Interferometer(MZI) waveguide is designed. The use of the double-arms MZI structure, effectively reduced the noise and distortion of signal brought by environment and temperature.Firstly, the transmission principle of ARROW waveguide is expatiated, equal-arms MZI pressure sensors sensing principle is analyzed, the elastic properties of thin-film and the coupling relationship between optics and mechanical are detailed studied. The relationship between output of light intensity changes and phase changes is discussed, and its expression is derived.Secondly, because the transmission loss of a great influence on the performance of sensor, each structural parameters of waveguide are designed. Based on the structure of ARROW waveguide principle impact on the transmission loss and previous experimental results, the low-loss single-mode rid waveguide is designed. The angle of MZI Y-branch is about 1°.Thirdly, according to elastic mechanics plates and shells theory, the stress distribution in elastic film is analysed and simulated by using MATLAB software. Influence of elastic film size on surface stress distibution and refractive index in sensing arm is studied, an intuitive and reliable result is obtained. It provides theoretical basis for the position of sensing arm on elastic film. The use of finite element analysis methods and ANSYS simulation software, the elastic film of MZI-based MOEMS pressure sensor is analyzed, the relationship among phase changes in sensing arm caused by photoelastic effect, size of elastic film, position of sensing arm and external pressure. On the basis of the above analytical results, the desirable position of the sensing arm should be the long edge of the elastic film. The optimal size of the elastic film should be 2800μm×1800μm×60μm. When the input optical wavelength is 0.6328μm, the half wave pressure of this sensor is 0.6MPa.Finally, a summary of this work is included and the prospect of future research work is carried out togeher.