Optical Cavities for Optical Atomic Clocks, Atom Interferometry and Gravitational-Wave Detection

Abstract

It is an extremely exciting time for physics. In the last 100 years we moved from the formulation of Einstein’s general relativity to the first direct observation of gravitational waves in late 2015 by the Laser Interferometer Gravitational-wave Observatory (LIGO). In that time we learned to use light to cool atoms to nearly absolute zero temperature, and to use atomic transitions in the microwave and optical regimes to devise the most accurate time and frequency references. We observed the wave-like behaviour of cold atoms in diffraction experiments using the periodic structure of light beams. Exploiting this wave-like behaviour, we constructed atom interferometers which allow us to test and measure gravity in a new scale. All of these experiments have one thing in common, from LIGO’s giant 4 km arms, to the transportable atomic clocks sent to space, they all make use of a device that has become essential in many areas of science and technology: the Fabry-Perot optical cavity. This thesis delves deeply into the application of optical cavities at the forefront of experimental physics, and it is divided into three parts, each pertaining to a different field where optical cavities are a key technology.