arXiv:2109.08444 · Physical Review A
Optimal orientation detection of an anisotropic dipolar scatterer
Felix Tebbenjohanns, Andrei Militaru, Andreas Norrman, Fons van der Laan, Lukáš Novotný, Martin Frimmer
Abstract
The angular orientation of an anisotropic scatterer with cylindrical symmetry in a linearly polarized light field represents an optomechanical librator. Here, we propose and theoretically analyze an optimal measurement scheme for the two angular degrees of freedom of such a librator. The imprecision--back-action product of this scheme reaches the Heisenberg uncertainty limit. Furthermore, we propose and analyze a realistic measurement scheme and show that, in the absence of spinning motion around the symmetry axis, measurement-based ground-state cooling of the rotational degrees of freedom of an anisotropic point scatterer levitated in an optical trap is feasible.