Towards deployable atomic gravimeters for geophysics

Many types of gravimeters are used in geophysics for gravity surveying, mineral prospecting, seismology and natural disaster monitoring. Atomic gravimeters use mater-wave interferometry, and are more accurate and have better long-term stability than gravimeters based on springs, superconducting coils or falling cubes. Since current atomic gravimeters are too complicated to operate outside a well-controlled laboratory, we have implemented an atom interferometer using only one laser diode and a pyramidal mirror, allowing for the instrument to be simple, compact and transportable. The pyramidal mirror is used to create a magneto-optical trap (MOT), and this reduces the number of incident laser beams on the MOT region to a single retro-reflected beam. Operating as a gravimeter, we have achieved sensitivities of 6 \textmu m/s2/$\surd $Hz. To ensure better transportability and reliability, we are developing an upgraded pyramid-based atomic gravimeter. Our simple and transportable design will open up applications in geodesy and geology.