Thermally induced bias error due to strain inhomogeneity through the fiber optic gyroscope coil

One of the performance limits of a navigation grade fiber optic gyroscope is the bias error due to the thermal sensitivity of the fiber coil. Thermal stress inside the fiber coil is an important source of the bias error. The reduction of the total stress inside the fiber coil can be limited. In this paper, it is shown that further improvement can be achieved by controlling the strain inhomogeneity through the fiber coil. A validated simulation environment is presented for strain distribution analysis. Thermally induced bias error formation mechanisms are compared. The effect of the strain inhomogeneity is reduced by presenting a different coil cross section and spool material. Experiments utilizing a coil design with better performance are presented for the verification of the approach.