High thermal conductivity and low stress potting adhesive for high precision optical fiber coil and its influence on the shupe error of FOG

Abstract

In order to meet the temperature performance requirements of high-precision FOG, the Shupe coefficient of the optical fiber coil must be further reduced. The generation of Shupe error is not only related to the rate of change of temperature with time, but also related to the rate of change of thermal stress with time. In this paper, the effects of thermal conductivity and internal stress of the potting adhesive on the Shupe error of the optical fiber coil were carried out. By designing a hyperbranched molecular structure, the curing stress of the UV potting adhesive was greatly reduced, and a rigid-flexible block structure was prepared by adjusting the formulation components to obtain high modulus (Eˊ) and high glass transition temperature (Tg) performance, which greatly improved the full temperature stability and long-term reliability of the potting adhesive. The potting adhesive is doped with high thermal conductivity particles to obtain high thermal conductivity, reduce the temperature gradient inside the optical fiber coil, and improve the full temperature performance of the coil. The results showed that the glass transition temperature of the developed high-precision optical fiber coil UV potting adhesive is higher than 100℃, and the Young's modulus is higher than 2000MPa. The peak-to-peak value of the coil Shupe is 0.1°/h. Through research, low stress, high thermal conductivity potting adhesive can effectively reduce the Shupe error of the high-precision optical fiber coil, improve the full-temperature performance of the coil, and realize the long-term stability and reliability of the FOG.