Manipulation of colloidal gold nanoparticles in the evanescent field of a channel waveguide

Colloidal gold spheres of radius 10 nm are reported to move forward in water, under the influence of radiation pressure forces, due to the evanescent field at the surface of an optical channel waveguide. The velocity is linearly dependent upon the optical power in the waveguide, acquiring a maximum velocity of 4 μm/s for modal power of 500 mW in the TM polarization at a wavelength of λ=1.047 μm.