More Power to Atom Interferometry

Abstract

Atom interferometry, in which atomic waves are coherently split and later recombined, has been called the Swiss Army knife of atomic physics because of its numerous applications [1]. Atom interferometers can be used to study gravity, observe quantum effects, and measure fundamental constants. However, the spitting of atomic beams has always been a challenging task. Several beam splitters for atoms have been developed over the years, many of which rely on complex, high-powered lasers whose photons collide with atoms to steer them along separate beam paths. Paul Hamilton and colleagues at the University of California, Berkeley, have built a more versatile beam splitter by using, for the first time, an optical cavity [2]. Laser pulses bounce back and forth inside the cavity, increasing the effective power in standing waves of light and reducing imperfections in the wave fronts. The light concentration within the cavity allows the use of common low-powered lasers for the initial pulses. The new design may lead to a universal atom interferometer with optical gratings that works with a wide range of atomic species.