MODELING OF OPTICAL TRAPPING USING DOUBLE NEGATIVE INDEX FISHNET METAMATERIALS

We calculate the optical forces exerted on nanoparticles in close proximity to the surface of flshnet metamaterials based on metal/dielectric/metal fllms when irradiated at near infrared wavelength. These forces show resonant frequencies similar to the magnetic resonant frequencies in the double negative index flshnet metamaterial. We also show that the optical force can be enhanced by optimizing the geometry of the flshnet to provide a stronger magnetic resonant dipole. In contrast to most other plasmonic nanostructure which always obtaining trapping force using an electrical resonant dipole, our presented structure utilizes the magnetic resonance to provide a trapping force. We have found that it is suitable for optical trapping of nanoscale particles at illumination intensities of just 1mW/"m 2 and the force is su-cient to overcome gravity.