Device for measuring a quantity representative of a population of cold atoms and associated sensor

Abstract

A device for measuring a quantity representative of a population (N) of cold atoms, the cold atoms being located in a cloud of cold atoms to be analyzed, the device includes a microwave source configured to generate an incident signal at a predetermined signal frequency, a microwave guide configured to propagate the incident signal and an antenna configured to emit the incident signal to the cloud of cold atoms and its environment, the antenna and the microwave guide also being able to recover an atomic reflected signal resulting from a reflection of the incident signal by the cloud and its environment, and which propagates in the waveguide in the opposite direction to the incident signal, a splitting device coupled to the microwave guide and configured to extract at least part of the atomic reflected signal, a detector configured to detect the atomic reflected signal extracted by the splitting device, the quantity representative of the population of cold atoms (N) being obtained from a detected value of the atomic reflected signal and from a detected value of a signal reflected by the environment in the absence of the cloud, called reference reflected signal.