Long-Term Stability of an Area-Reversible Atom-Interferometer Sagnac Gyroscope

We report the first demonstration of a matter-wave interference gyroscope that meets both the short-term noise and long-term stability requirements for high accuracy navigation. This performance level resulted from implementation of a novel technique to precisely reverse the input axis of the gyroscope.

Figure 1

(a) Typical interference fringes. Upper trace: copropagating atomic beam. Lower trace: counterpropagating atomic beam. (b) The square root of the spectral density of the cultural rotation noise in the laboratory.

Figure 2

(a) Measured phases over a $2\times {10}^4\sec$ period. The interferometer phase of the case-reversed (case 1) trace has been multiplied by $-1$ such that a positive phase change indicates a positive rotation change in both traces. The dark trace indicates the case-compensated output. (b) Allan deviation for the interval between $9\times {10}^3$ and $1.6\times {10}^4\sec$.

Figure 3

(a) Case-compensated output (light line) and correlation signal (dark line) consisting of a linear sum of five temperature measurements. (b) Temperature-compensated rotation output. (c) Allan deviation for the case-compensated (dashed line) and temperature-compensated (solid line) signals.

Figure 4

The standard (solid circles), case-reversed (open circles), and case-compensated outputs (triangles) for (a) longitudinal displacement of the $\pi$ pulse, (b) vertical deflection of the first $\pi =2$ laser beam retro-reflection, (c) fractional change in Raman laser intensity, and (d) magnetic field bias current.