12 October 2015
The main goal of this project was to demonstrate the possibility for atom interferometers to go beyond the present limits of inertial sensors based on standard technologies (mechanical or optical) and reducing drastically the complexity of cold atom setups in the same time. As for atomic clocks, which nowadays provide time and frequency standards all around the world, future atom inertial sensors have to be compact, transportable and autonomous. The project is realized in the frame of Miniatom collaboration with LP2N (Philippe Bouyer) and IXSEA, KLOE, Thales and III-V Lab companies.
Among all the developments done in the project Miniatom, SYRTE laboratory has especially participated to develop a compact gravimeter. The design of the physical package of the sensor is based on a novel architecture based on an empty pyramid enabling the use of a unique laser beam to realize all the functions of the interferometer. It leads to a drastic simplification of the setup a well for the vacuum chamber as for the optical bench. The size reduction of the head of the sensor is by more than two order of magnitude, to be reduced below 2l. Similar simplification has been done to the optical bench used for the cooling and manipulation of atomic wave-packets and to the micro-wave frequency reference for the Raman transitions. Finally, we have demonstrated the interest of hybridizing matter-wave and classical accelerometers that avoids any vibration isolation platform. The hybrid sensor benefits from long term stability and accuracy from the first and high dynamic and bandwidth from the second. This method is very promising for field applications and specially inertial navigation.
- Scheme of the principle of work of the compact gravimeter
- The atoms are first cooled down inside the pyramid and let fall under gravity. The interferometer is realized by the laser beams going up and down, issue from the refection in the pyramid.
J. Lautier, L. Volodimer, T. Hardin, S. Merlet, M. Lours, F. Pereira Dos Santos, and A. Landragin, « Hybridizing matter-wave and classical accelerometers », Applied Physics Letters 105, 144102 (2014).
J. Lautier, M. Lours, A. Landragin, « A compact micro-wave synthesizer for transportable cold-atom interferometers », Rev. Sci. Instrum. 85, 063114 (2014).
Q. Bodart, S. Merlet, N. Malossi, F. Pereira dos Santos, P. Bouyer, and A. Landragin, « A cold atom pyramidal gravimeter with a single laser beam », Applied Physics Letters 96, 134101 (2010).