Sensitive To Ring The Key Technology Of Re-entry Micro-optical Gyroscope, Sagnac Effect

Following the development of the Micro-Nano technology and photonics technology, the manufacturing technology of integrated optical and optoelectronic devices has a great advance. And the micro-optical gyro, which is suitable for mass production,has become an important trend in the development of inertial measurement devices. At present, there are three kinds of the program on micro-optical gyro which are studied extensively in domestic and foreign research institutions, such as Micro-Ring Laser Gyroscope, Resonant Micro Optical Gyroscope, Re-entrant Interferometric Micro Optical Gyroscope(RE-MOG).And compared with other gyro structures, there are some advantages in the Re-entrant gyroscope. Firstly, in principle Re-entrant gyro is similar with IFOG, so there are much same treatment in many problems between Re-entrant gyro and IFOG, such as light source selection, back scattered light control, design of peripheral circuits etc. Secondly, Research objective is very clear in Re-entrant micro-gyroscope, which is miniaturization and integration. So, problems caused by miniaturization and integration are the main work of this paper, which are the control of polarization error which is realized by maintaining waveguide and the loss of signal light in waveguide which is improved by introduction of Erbium-doped waveguide amplifier (EDWA). So, the main work in this paper is following:Firstly, starting from Sagnac effect, basic principles of interferometric optical gyro and signal modulation and demodulation scheme are reviewed. Then, the signal detection theory of RE-MOG is derived in detail, and the extraction program of Re-entrant signal is given. Additionally, some error factors leading to non-reciprocity phase error, such as polarization, back scattering and Kerr effect, are discussed in details.Secondly, the stress birefringence in Sagnac effect sensitive ring (SSR) is analyzed in details to design maintaining waveguide. Based on elastic-optic effect, the relationship between birefringence and stress is given. Then, in details birefringence is analyzed from the structure and materials in Si/SiO2 waveguide and SOI (Silicon On Insulator) waveguides. And to design maintaining waveguide, the methods of increasing birefringence are proposed.Lastly, Erbium-doped waveguide amplifier is emphasized to improve the weak power of re-entrant signal light, which is caused by waveguide loss and the output of coupler. Through the design of coupler, the splitting ratio is determined, the power of re-entrant signal light is optimization, and the detection sensitivity of signal light is improved. Then, EDWA is optimized based on gain characteristics from waveguide length, doping concentration, pump power and signal power.