【摘要】 垂直光纤环面变化的轴向磁场会降低去偏陀螺的精度,因此提出减小轴向磁场灵敏度的新方法:用交叉绕法单模光纤环作为敏感环。与普通绕法相比,理想交叉绕法光纤环中的正反任一束光经过的路径可分为相等的两段,每段路径上产生的Faraday相位延迟大小相等、符号相反,整个路径上相互抵消,从而两束光不存在与磁场有关的Faraday非互易相位差。仿真结果表明,交叉环有很低的轴向磁场灵敏度,与轴向磁场灵敏度为23.4°/(h·mT)的普通环相比,其他参数相同、不对称度为1%的交叉二极子光纤环,轴向磁场灵敏度仅为0.23°/(h·mT)。更多还原

【Abstract】 Since the axial magnetic field that is varied and perpendicular to the endface of fiber can reduce the precision of Fiber-optic Depolarized Gyro, the new method is put forward by using across-winding single-mode fiber loop to replace normal-winding one in Gyro to decrease the axial magnetic field sensitivity. Compared with the normal-winding fiber loop, the route through which each of the two clockwise and counterclockwise light beam propagates in the perfect across-winding fiber loop can be divided into two sections with same length, and in each of the sections the Faraday phase retards are equal in magnitude and opposite in sign, so they counteract in the whole fiber. As a result, the two beams of light don’t have Faraday nonreciprocal phase error. The emulation result proves that across-winding loop is lowly sensitive to the axial magnetic field. In contrast with the normal-winding loop whose axial magnetic sensitivity is 23.4°/h/mT(1mT=10-3Tesla),the across-dipole-winding single-mode fiber loop with 1% degree of dissymmetry is sensitive to the axial magnetic field at 0.23°/h/mT. However, the parameters of the across-dipole-winding loop are the same as that of the normal-winding loop.更多还原