Prospects for Precise Measurements with Echo Atom Interferometry

Abstract

Echo atom interferometers have emerged as interesting alternatives to Raman interferometers for the realization of precise measurements of the gravitational acceleration g and the determination of the atomic fine structure through measurements of the atomic recoil frequency ω q . Here we review the development of different configurations of echo interferometers that are best suited to achieve these goals. We describe experiments that utilize near-resonant excitation of laser-cooled rubidium atoms by a sequence of standing wave pulses to measure ω q with a statistical uncertainty of 37 parts per billion (ppb) on a time scale of ∼50 ms and g with a statistical precision of 75 ppb. Related coherent transient techniques that have achieved the most statistically precise measurements of atomic g-factor ratios are also outlined. We discuss the reduction of prominent systematic effects in these experiments using off-resonant excitation by low-cost, high-power lasers.

Navigation-Compatible Hybrid Quantum Accelerometer Using a Kalman Filter

“…These systems are limited by slow drifts of the biases inherent to their inertial sensors, which ultimately lead to large speed and position errors after integration. Currently, the long-term bias stability of navigation-grade accelerometers is on the order of 10 µg-which, in the absence of aiding sensors such as satellite navigation systems, leads to horizontal position oscillations of 60 m at the characteristic Schuler period of 84.4 minutes [1,2].Since their first demonstration in the early 1990s, atom interferometers (AIs) have proven to be excellent absolute inertial sensors-having been exploited as ultra-high sensitivity instruments for fundamental tests of physics [3][4][5][6][7][8], and as state-of-the-art gravimeters with accuracies in the range of 1 − 10 ng achieved both in laboratories [9][10][11][12][13][14] and with compact transportable systems [15][16][17][18][19]. As a result, they have been proposed for the next generation of inertial navigation systems [20][21][22][23].…”

Laboratory Courses on Laser Spectroscopy and Atom Trapping

“…These students have completed a variety of research projects at the undergraduate level [49][50][51][52][53][54][55][56][57][58]. Some of the contributions of graduate students are reviewed in References [64,82].…”

“…These lasers can be hermetically sealed and pumped down to very low pressures, enabling more stable locking techniques [62,63]. They are suitably stable for measurements of gravitational acceleration using a falling corner cube gravimeter (Scintrex FG5X) [64] and are also easily integrated into the MOPA system for experiments which require greater optical power [65]. The number of atoms that can be loaded into a vapor cell MOT with a laser beam diameter d is known to scale as d x , where x is typically larger than 3 [66].…”

Characterization and applications of auto-locked vacuum-sealed diode lasers for precision metrology

“…These include industrial magnetometry, 42 precise determinations of atomic lifetimes, 43 and atom interferometry with cold atoms. 28…”

“…Our design has addressed this limitation by allowing the laser cavity to be pumped out. [28][29][30] To bring the laser cavity back into alignment after pump-out, we use a vacuumcompatible feedthrough to realign the angle of the IF from outside the cavity to compensate for the change in the refractive index.…”