Self-alignment of a compact large-area atomic Sagnac interferometer

Abstract

We report on the realization of a compact atomic Mach-Zehndertype Sagnac interferometer of 13.7 cm length, which covers an area of 19 mm 2 previously reported only for large thermal beam interferometers. According to Sagnac's formula, which holds for both light and atoms, the sensitivity for rotation rates increases linearly with the area enclosed by the interferometer. The use of cold atoms instead of thermal atoms enables miniaturization of Sagnac interferometers without sacrificing large areas. In comparison with thermal beams, slow atoms offer better matching of the initial beam velocity and the velocity with which the matter waves separate. In our case, the area is spanned by a cold atomic beam of 2.79 m s −1 , which is split, deflected and combined by driving a Raman transition between the two hyperfine ground states of 87 Rb in three spatially separated light zones. The use of cold atoms requires a precise angular alignment and high wave front quality of the three independent light zones over the cloud envelope. We present a procedure for mutually aligning the beam splitters at the microradian level by making use of the atom interferometer itself in different configurations. With this method, we currently achieve a sensitivity of 6.1 × 10 −7 rad s −1 Hz −1/2 .

Overcoming loss of contrast in atom interferometry due to gravity gradients

“…The potential of light-pulse atom interferometry [1,2] for high-precision measurements has been amply demonstrated with its successful implementation in extremely sensitive inertial sensors, including gyroscopes [3][4][5], gradiometers [6] and the currently most precise absolute gravimeters [7][8][9]. It has already found applications in accurate measurements of fundamental constants [10][11][12][13][14][15] and tests of fundamental properties [16][17][18], and it is a key ingredient in plans for future tests of the equivalence principle in space [19,20] (atom-interferometry-based experiments have already been performed on the ground [21][22][23][24]), next-generation satellite geodesy missions [25] or even alternative proposals for gravitational-wave detection [26].…”

Erratum: A high-flux BEC source for mobile atom interferometers (2015 New J. Phys. 17 065001)

“…In recent years, an excellent degree of control over ensembles of ultra-cold atoms has been demonstrated. By exploiting the wave character of atomic ensembles that is dominant on such temperature scales, atoms have been used as highly sensitive probes for a variety of physical quantities such as the gravitational constant G [3,4] and the fine-structure constant [5], as well as the measurement of accelerations [6][7][8] and rotations [9][10][11][12][13]. While the accuracy of atom interferometers has improved to compete with classical tests, they also serve as complementary tools, as they may explore new physics and the fundamental structure of matter in the quantum regime.…”

Compact atomic gravimeter based on a pulsed and accelerated optical lattice

“…Combining this method with an atomic elevator allows us to measure the local gravity at different positions in the vacuum chamber. This method can be of relevance to improve the measurement of the Newtonian gravitational constant G. Atom interferometry has proven to be a reliable method to realize robust inertial sensors [1][2][3][4][5][6][7][8][9]. The performance of these devices rivals state-of-the-art sensors based on other methods.…”