Research On Closed-loop FOG By Double-Y Multifunctional Integrated Optic Device

In this paper, a new kind of fiber-optic gyroscope (FOG), which uses a double-Y multifunctional integrated optic device (MIOD), is proposed and researched. The key technology of MIOD and the effect of performance of MIOD on FOG are studied. The light path and electronic circuit of FOG are designed, and the performance of FOG is tested.Firstly, technology and principal performance are analized. With an analog sawtooth closed-loop signal processing approach, the effect of the additional intensity modulation of MIOD, polarization cross coupling because of misalignment of principal axes between fiber pigtail and Y branch, back reflecting etc of MIOD on FOG are studied. The methods to solve these problems are proposed.Secondly, the FOGs, including reciprocal light path and electronic circuit with core device FPGA, are designed and realized. According to the relationship between phase bias and noise, the optimum phase bias are analized and proved by experiments.At last, the characteristics over temperature, stability and reliability of double-Y MIOD are experimently studied and the performances of the FOG with double-Y MIOD are tested. All these make a basis for the integrated FOGs.