Direct measurement of torque in the optical trap

Principal Investigator: Pál Ormos
This project is part of the EU-FP6 cooperation ATOM-3D

If a flat object is grabbed in an optical trap formed by linearly polarized light, it will be oriented due to the anisotropic scattering of polarized light. An object of general shape corresponds to a brick: it has a longest, second longest and shortest dimension. The position in the oprical trap is such that the longest dimension points in the direction of the light propagation and the second longest in the plane of polarization.



This phenomenon gives additional control in the optical manipulation of microscopic particles.