Latest update : 1 April 2015.
Large area atomic gyroscope
This new gyroscope experiment is based on a fountain configuration with 4 pulses to manipulate the atomic wave packets and which enables for a very large area of the interferometer. It relies on the use a single atomic sources launched along the vertical direction and which trajectory is bend by the gravity.
- Picture of the new experimental setup, based on a fountain configuration with 4 pulses and giving access to one horizontal component of rotation with a very large sensitive interferometer area.
The atom wave-packets undergo a succession of four Raman pulses to manipulate the atomic wave-packets. The gravity bends the atomic trajectories such the two loops add there sensitivity to the Sagnac effect. The interferometer is then sensitive to one horizontal component of rotation with only one atomic source and without being sensitive to acceleration. This configuration enables to increase the measurement time, enlarging the interferometer area by more than two orders of magnitude to 11 cm2. Recent results already demonstrated record long term stability for a cold atom interferometer, at the 1 nrad.s-.1 level
Phys. Rev. Lett. 116, 183003 (2016)
- Schematic of the principle of continuous cold-atom gyroscope. Continuous measurement is performed with a joint interrogation sequence where the atomic beam splitter is shared between the clouds entering and exiting the interrogation region.
This new setup gives the possibility to test the intrinsic limits of such interferometers. This is needed to use this kind of gyroscope for applications such as inertial navigation or geophysics. In particular, for the first time we have demonstrated the advantage in measuring continuously with an cold atom interferometer, which will enable the sensitivity in removing the aliasing effect in such sensors.
Phys. Rev. A 90, 063633 (2014)
Indeed, the expected performances should open the possibility of measuring fundamental parameters in geophysics, still inaccessible to the experiments, such as fluctuations of direction of the Earth’s rotation axis at intermediate time scale (few hours).