Figure 5

Atom interferometry in a rotating environment. Left: Schematic of a double-diffraction atom interferometry sequence [120] in a rotating environment with angular velocity Ω. The picture shows different snapshots of the sequence at three different times. The atoms (blue) are coherently split at the time \(t=0\) by a retro-reflected light beam (red) with wave numbers \(k_{1}\) and \(k_{2}\). The dotted blue line depicts the trajectory of the atoms. The atomic momentum \(k_{\mathrm{eff}}=k_{1}-k_{2}\) is reversed at \(t=T\) and another splitting pulse is applied at \(t=2T\). The rotation causes the clouds to not perfectly overlap, which reduces the contrast. Right: The tip-tilt stage used for rotation compensation. The titanium cylinder has a 25.4 mm diameter and a length of 53.5 mm, and contains four piezo actuators. They move the mirror with a full stroke of ±2 mrad. To reduce positioning inaccuracies, strain gauges are applied to the piezo actuators. This allows for closed-loop operation of the stage, giving lower positioning inaccuracies for long times without re-calibration