Release and recapture of silica nanoparticles from an optical trap in weightlessness

Optically trapped silica nanoparticles are a promising tool for precise sensing of gravitational or inertial forces and fundamental physics, including tests of quantum mechanics at "large" mass scales. This field, called levitated optomechanics can greatly benefit from an application in weightlessness. In this paper, we demonstrate the feasibility of such setups in a microgravity environment for the first time. Our experiment is operated in the GraviTower Bremen that provides up to 2.5 s of free fall. System performance and first release-recapture experiments, where the particle is no longer trapped, are conducted in microgravity. This demonstration should also be seen in the wider context of preparing space missions on the topic of levitated optomechanics.