Research On MMI-based Opto-electric Hybrid Integrated Three-component Seismic Acceleration Sensing Technology

Oil and gas is the most important energy sources in the world, and it is the key to sustainable development of a country. In order to realize the high accuracy seismic exploration, three-component seismic exploration is used to find the oil and gas storage in the underground. The multi-component seismic exploration requires three-component seismic signals, which are measured by three-component geophone in an earthquake. And meanwhile, meet the three-dimensional signal acquisition requirements, which mean high resolution capability, high signal-to-noise ratio, high fidelity, high definition, high accuracy and high confidence.In this thesis, a three-component hybrid-integrated optical acceleration seismic geophone based on MMI is introduced for the first time, which contains the photo-elastic waveguide integrated technology and 3-component seismic signal detection technology, have great significance in seismic exploration and inertial navigation, and so on. Firstly, the article designed the overall structure, three-component simple harmonic oscillators and sensitive unite, based on the theory for design the three-component hybrid-integrated optical acceleration seismic geophone, the dynamic and static features have been calculated as well. And based on the one-dimensional photoelasitcity when one-dimensional stress is applied on LiNbO3 crystal, we derive the 3-dimensional photoelasitcity when 3-dimensional stress is applied on LiNbO3 crystal, and analyse the level of sensitivity to off-axis accelerations, design the three-component hybrid-integrated optical acceleration seismic geophone whose cross-sensitivity is 0. Then, design niobate lithium a single-mode ridge waveguide with effective index method, and verified structural parameters by numerical simulation. And learn the multimode interference theory, clear the imaging mechanism of multimode interference couplers, and the design of 1 × 4 multi-mode coupler, the structure parameters are optimized through BPM simulation, and the uniformity is 0.0997dB, and use it design the double M-Z interferometer chip based on MMI, and use BPM simulation, analysis the optical field distribution on the acceleration modulation, and difference calculation of the output signals show the result of differential processing and modulation acceleration is the relationship of sine. And finally, in order to make a good Mach-Zehnder interferometer with annealed proton-exchanged lithium niobate waveguide, lots of theoretical and experimental researches on process craft of waveguide interferometer have been done, a feasible process flow is made and valuable technological parameters are obtained.