Theoretical And Experimental Research On The Michelson Interference Integrated Optical Acceleration Seismic Geophone

The research of inspecting earthquake and geologic prospecting is very importantfor safeguarding the living circumstances of human being and prospecting for the oiland natural gas resources. In order to obtain higher inspecting precision, it should besupported by many other subjects, such as sensor researching, optics, signalprocessing, and so on. This paper "Theoretical and experimental research onMichelson interference integrated optical acceleration seismometer" is the sub-projectof a subject imbursed by Natural Science Foundation of China (serial number:49874031). The purpose of this paper is to research a new Michelson interferenceintegrated waveguide seismometer in which integrated optics and digital signalsprocessing technics are applied to inspect acceleration and seismic waves. Theseismometer with high precision ensures the veracity of inspecting seismic waves andgeologic prospecting. Main research tasks of this paper are as following:The theory of the Michelson interference integrated optical accelerationseismometer is studied in this paper. strain effect , Poisson effect and elasto-opticeffect caused by lateral stress in fibers are analyzed, and the phase change of thelight-wave in fibers is discussed deeply. The relation between the phase change of thelight-wave and the stress strain of the fiber is deduced, and the relation between theoptical intension of the system output and the acceleration is deduced also byestablishing the function which expresses the relation between the acceleration andthe phase. Static and dynamic states of the system are researched, and the analyse andthe design calculation of static sensitivity and frequency characteristic are finished. Acapable transverse spring is schemed out to avoid the transverse vibration effectively.A smooth frequency response curve is obtained by testing.The design plan of the integrated optical chip of Michelson interferenceacceleration seismometer is advanced for the first time. The design of the symmetricaldouble Y-branch annealed proton exchange waveguide is done. The bend loss of thewaveguide is analyzed deeply, and the waveguide with "S" joints is designed based onthe relation between the output power and the branch angle in the waveguide toreduce the connection loss. According to the linear electro-optic effect of the X cut Ytransfers LiNbO3 crystalloid, and considering technical requests and the phasemodulation characteristic of the hybrid-integrated Optical accelerometer, Gather typemodulator is developed. Innovations in this paper are as following:A complete new interagrated waveguide sensor is put forward. Theoreticalresearch and system integration of Michelson interference integrated optical -opticalfiber acceleration seismometer are finished. The special Michelson interferenceintegrated optical chip of acceleration seismometer is developed.A harmonic oscillator with high sensitivity and good transverse anti-vibrationperformance is developed. It is hybrid-integrated with integrated optical chip, LD andPIN, and a new integrated detector testing system with stable performance, highprecision is developed successfully.The fabrication technics of the chip is researched deeply and lot of experimentsare done. A new method of eroding aluminium film, through combining two steps ofdeveloping and eroding under normal temperature, is created. This method has lessside-eroding effect and more smooth waveguides could be made by it.