Precision measurements with levitated optomechanics

The isolation of levitated optomechanical systems from their environment makes then attractive for measurement of weak forces, but also makes them challenging to precisely measure relative to the outside world. We will discuss optical techniques for precision measurement of the displacement of a particle levitated in a magneto-gravitational trap, for calibrating the magnification of realistic optomechanical systems, and for accurately locating a levitated particle relative to objects outside of the vacuum chamber containing the system.