Mark A. Kasevich

Method of phase extraction between coupled atom interferometers using ellipse-specific fitting

We present a method of analysis involving ellipse-specific fitting of sinusoidally coupled data from two gravimeters in a gradiometer configuration. This method permits rapid extraction of induced gradient phase shifts in the presence of common-mode vibrational phase noise. Gravity gradients can be accurately measured in the presence of large vibrational accelerations.

Bayesian estimation of differential interferometer phase

We apply Bayesian logic to optimally estimate the differential phase in a discrete-time, dual-interferometer measurement. This method is particularly relevant to the case of a gravity gradiometer, where the gravity gradient between cold-atom fountain interferometers can be estimated from the differential phase, despite the presence of large common phase (acceleration) fluctuations. Given an accurate model, the bias-free algorithm we present is optimal and leverages experimental knowledge of the system noise, classical or quantum, to outperform other typical estimators, including ellipse-fitting techniques.

Field Emission Tip as a Nanometer Source of Free Electron Femtosecond Pulses

We report a source of free electron pulses based on a field emission tip irradiated by a low-power femtosecond laser. The electron pulses are shorter than 70 fs and originate from a tip with an emission area diameter down to 2 nm. Depending on the operating regime we observe either photofield emission or optical field emission with up to 200 electrons per pulse at a repetition rate of 1 GHz. This pulsed electron emitter, triggered by a femtosecond oscillator, could serve as an efficient source for time-resolved electron interferometry, for time-resolved nanometric imaging and for synchrotrons.

Sensitive absolute-gravity gradiometry using atom interferometry

We report the demonstration of a sensitive absolute-gravity gradiometer based on light-pulse atom-interference techniques. The gradiometer consists of two absolute accelerometers operated in a differential mode. We report a differential acceleration sensitivity of

Measurement of the gravitational acceleration of an atom with a light-pulse atom interferometer

4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}g/{\mathrm{Hz}}^{1/2}

Rotation sensing with a dual atom-interferometer Sagnac gyroscope

and an inferred differential acceleration accuracy of less than

Ultrafast electron pulses from a tungsten tip triggered by low-power femtosecond laser pulses.

{10}^{\ensuremath{-}9}g.

Multiaxis inertial sensing with long-time point source atom interferometry.

This corresponds to a gravity-gradient sensitivity of

Atomic gravitational wave interferometric sensor

4E/{\mathrm{Hz}}^{1/2}