Hybridizing matter-wave and classical accelerometers

Abstract

We demonstrate a hybrid accelerometer that benefits from the advantages of both conventional and atomic sensors in terms of bandwidth (DC to 430 Hz) and long term stability. First, the use of a real time correction of the atom interferometer phase by the signal from the classical accelerometer enables to run it at best performances without any isolation platform. Second, a servo-lock of the DC component of the conventional sensor output signal by the atomic one realizes a hybrid sensor. This method paves the way for applications in geophysics and in inertial navigation as it overcomes the main limitation of atomic accelerometers, namely the dead times between consecutive measurements

Gyromètre à atomes froids de grande sensibilité

“…Dans ces résultats préliminaires, le rapport signal à bruit est ici limité par le bruit de détection associé au plus faible contraste de l'interféromètre à plus grand temps d'interrogation (10 % contre 17 %), et par le bruit de rotation non pris en compte, de sorte que la sensibilité à court terme du gyromètre n'est pas encore améliorée par rapport à la configuration où 2T = 480 ms. L'amélioration de la sensibilité est en court. Au-delà du travail sur l'augmentation du contraste, nous mettons en oeuvre actuellement un système de compensation en temps réel des vibrations, permettant de rester à flanc de frange de l'interféromètre en rétroagissant sur la phase des lasers Raman à partir du signal de phase calculée [17]. Un niveau de stabilité à 10 000 s dans la gamme des 10 −10 rad·s −1 devrait être atteint d'ici la fin de l'année 2016.…”

Determining optical path difference with a frequency-modulated continuous-wave method

“…The phase noise of the Raman laser system after implementation of zeroing of the OPD is also measured. With equivalent area, atomic interferometer gyroscopes are ∼10 10 times more sensitive to phase shifts induced by inertial effects [1], such as rotation [2,3] or acceleration [4][5][6], compared with their optical counterparts such as fiber-optic and ring laser gyroscopes. The key elements to construct such a practical atom interferometer are the beam splitters and the mirrors to manipulate cold atoms [7].…”

Atom Interferometry in a Warm Vapor

“…In this setting, the matter wave of each atom evolves with inertial freedom such that photon recoils may be used to coherently split and recombine the wave packets without perturbation. The experimental overhead is laser system complexity and ultra-high vacuum requirements that have challenged efforts fielding these instruments [14,[16][17][18][19][20].The simplicity of a vapor cell approach, used for atomic clocks [21] and magnetometry [22,23], is an alluring alternative. In this approach, long interrogation times are achieved through the use of a buffer gas or a spin antirelaxation coating.…”

“…In this setting, the matter wave of each atom evolves with inertial freedom such that photon recoils may be used to coherently split and recombine the wave packets without perturbation. The experimental overhead is laser system complexity and ultra-high vacuum requirements that have challenged efforts fielding these instruments [14,[16][17][18][19][20].…”