Interleaved Atom Interferometry for High Sensitivity Inertial Measurements

Inertial sensors based on atom interferometry address several applications ranging from navigation, geoscience, metrology and tests of fundamental physics. The major limitation of cold-atom sensors has been their reduced... [ view full abstract ]

Inertial sensors based on atom interferometry address several applications ranging from navigation, geoscience, metrology and tests of fundamental physics. The major limitation of cold-atom sensors has been their reduced sampling rate associated with dead times, which results in a degraded sensitivity due to vibration noise aliasing. Achieving higher sampling rate without degrading the sensor sensitivity has been a long-standing goal for applications where small signals varying on second time-scales or faster are of interest.

We report on the interleaved operation of a cold-atom inertial sensor, where 3 atomic clouds are interrogated simultaneously in an atom interferometer featuring a sampling frequency of 3.75 Hz and a high inertial sensitivity, as given by the 801 ms interrogation time of the atoms in the interferometer. Besides an increase in sensor bandwidth, we show that this operation mode allows us to efficiently average vibration noise and to demonstrate a record rotation sensitivity of 30 nrad/s/sqrt(Hz). Consequently, we can, for the first time, characterize and stabilize the systematic effects of a cold atom gyroscope in the low 10^-10 rad/s range, which establishes cold-atom gyroscopes as a promising alternative to current technologies for inertial navigation.

Our experiment validates interleaving as a key concept in future atom-interferometry sensors aiming at probing time-varying signals, such as in onboard inertial measurement units or gravity gradiometers, or gravitational wave detectors.