Behaviour of a non-spherical metal nanoparticle in an optical trap

Even though a nanoparticle is much smaller than the wavelength used for their spatial confinement in an optical trap, the nanoparticle shape strongly influences force interaction between the light and the nanoparticle. The nanoparticle orientation with respect to the beam propagation and polarization strongly influences the light scattering pattern and thus the acting optical forces and torques upon the nanoparticle. We demonstrate experimental and theoretical results concerning the optical trapping of metal nanoparticles and the influence of the trapping wavelength on shaped plasmonic nanoparticles.