Probing non-Newtonian gravity with optically levitated force sensors
The universal law of gravitation has undergone stringent tests for many decades over a significant range of length scales. However, on scales below a few tens of μm we are several orders of magnitude away from actually measuring gravitational forces. In this talk I will present the first investigation of the inverse-square law at these scales using an optically levitated test mass. The advantages of this technique and further applications will be shown, but emphasis will also be on the technical challenges we face and possible improvements we are tackling in order to reach the full sensitivity of the technique.