PhD abstract
The understanding and multiple experimental demonstrations of atom interferometry have allowed the design and realisation of cold atom inertial sensors. These devices, initially intended for metrology and high-precision measurements, are now in the industrialization phase and constitute one of the pillars of the second quantum revolution. The first sensors were designed to operate in laboratories, and as such they are hardly suitable for field applications such as inertial navigation. The central objective of this thesis was therefore to study capacitance technologies for the realisation of compact inertial sensors. An atom chip was chosen as the key element of the physical package. It allows to reduce the size of sensors while giving the possibility to have a cold or ultra-cold coherent source of atoms and the realisation of different functions necessary for atomic interferometry. First, the manuscript discusses the cooling and preparation of atoms in a magnetic trap. . Secondly it presents the implementation of different laser beam based atomic optics elements, as well as the development of a given protocol for inertial rotation measurement with a linear magnetic guide. In particular, the experimental study of the coherent propagation of atoms in this guide is reported.
An essential factor in inertial navigation applications is the stability of inertial measurement units. This parameter is seriously affected by the dead time between measurements. As cold atom sensors have a significant dead time, due to the cooling process, the search for a possible solution to this problem was a subject of this work. Specifically, a new technique was implemented for the microwave and non-destructive measurement of the population of atomic levels used in an interferometer. This detection method leads to a significant reduction of the dead time over several interferometric measurement cycles, with a strong potential for integration on atom chips.
Key words
cold atoms, atoms interferometry, microwaves