Interferometric multi-core fiber optic gyroscope under temperature changing environment

We have proposed an interferometric fiber optic gyro (I- FOG) with a novel sensing fiber coil consisting of multi-core fiber (MCF) spliced with fan-in/ fan-out(FIFO) devices. This sensing coil can improve the sensitivity of I- FOGwithout escalating the hardship of winding process of fiber to form coils. We have fabricated a seven-core MCF coil with FIFO devices and demonstrated the proper operation of the proposed I- FOGfor the first time. The angular random walk performance of 0.002 deg/√h was achieved, thereby confirming that the seven-core waveguide loop works successfully as a Sagnac interferometer as expected. In addition, we evaluated the effect of temperature changes ofMCF and FIFO devices that cause fluctuations in the measured rotation rate. We confirmed that this effect shows essentially the same features as Shupe effect (non-reciprocal phase shift error due to changing environmental temperature) which is a well-known feature of conventional I- FOGs.