Barriers in the realization of anti-PT-symmetric optical gyroscope

We theoretically analyze the performances of the anti-PT-symmetric gyroscope near the exceptional point (EP). The results show that the frequency splitting caused by rotation is proportional to the square root of the fraction of power coupled from the bus to the ring. To fully exploit the potential of the EP, one needs to overcome two aspects of challenges. The first one is the preparation of sensitive unit, to detect the angular velocity of 10(4) deg / h with a micron-scale sensor; the allowable variation in the ratio of cavities' radii is within the order of 10( - 16), which is exceedingly challenging in current nano fabrication. The other is controlling environmental disturbances. A temperature variation of 0.002degree celsius would make the minimum detectable rotation rate up to 10(10) deg / h, which is far beyond practically applications. Our analysis points out the difficulties in realizing this gyroscope, which has significant referential values to future work.