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Antoine Godard

Publications and source records attributed to Antoine Godard.

2 recordsLinked to original sources

Characterisation of a triple-species 87Rb/85Rb/133Cs magneto-optical trap towards cold-atom interferometry

We present the simultaneous trapping and cooling of ${}^{85}$Rb, ${}^{87}$Rb and ${}^{133}$Cs in a triple-species magneto-optical trap (MOT). This demonstration is obtained using an all-fibre compact and robust laser system based on telecom 1.5 $\mu$m and 2 $\mu$m technologies. We characterise the two-body interspecies losses in the double and triple-species MOT. We calculate the two-body interspecies trap-loss coefficient for the ${}^{85}$Rb/${}^{133}$Cs and the ${}^{87}$Rb/${}^{133}$Cs pairs, representing a variation of less than 7 \% in atom number. No losses are observed between ${}^{85}$Rb and ${}^{87}$Rb in our experimental conditions. We find that interspecies interactions inside the triple-species MOT do not prevent trapping and cooling 10$^{8}$ atoms for each species, making our system suitable for future multi-species cold-atom interferometry applications.

physics.atom-ph

Impact of rotation on a cold atom interferometer and compensation strategy

Rotations play a detrimental role in achieving ultra-high-performance inertial measurements with an atom interferometer, leading potentially to a total loss of interference contrast and the emergence of dominant phase shift biases. This becomes particularly significant when considering operation in dynamic conditions such as those encountered in Earth orbiting satellites in the perspective of future space gravity missions on-boarding a cold atom accelerometer. We study in this context the impact of rotation on the phase shift and contrast of an atom interferometer and investigate mitigation strategies. An analytical model is derived and compared to experimental demonstrations carried out using an original setup in which the well-controlled proof-mass of a space electrostatic accelerometer is used as the retro-reflection mirror of a cold atom gravimeter. By properly counter-rotating the electrostatic proof-mass, we demonstrate for instance the possibility of recovering the interferometer contrast, otherwise equal to zero, to a level better than 90%, in both cases of constant angular velocities or in presence of angular accelerations. Our results demonstrate the possibility to perform high performance inertial measurements with a cold atom interferometer in a challenging environments.

physics.atom-ph