Hybridization between iXblue FOG and a 3D quantum accelerometer

For mobile operation of the hybrid accelerometer, it is crucial to compensate for rotations of the sensor head which easily prevent any measurement to be performed. Indeed, due to linear free-fall trajectory of the atomic clouds, a rotation of the reference frame would cause a bad overlapping of the wavepackets in the interferometer.

For this purpose, we installed low-noise, high dynamic range and sensitivity Fiber-Optics Gyroscopes (FOGs) along with high bandwidth, precision and stability piezo tip-tilt platforms.

The FOGs will allow a continuous measurement of rotation rate along the 3 measurement axes which, once integrated and converted, will drive the tip-tilt stages.

The goal is to correct the alignment of the reference mirror in real time during the interferometer in order to prevent the contrast loss, which is the main issue of undergoing rotations while performing cold atom inertial sensing.

Additionally, rotations measurements provide knowledge of Coriolis accelerations and authorize to feedback it onto the laser phase in real time, to ultimately track the central atomic fringe.