Optical manipulation of gold nanoparticles using an optical nanofiber

Gold nanoparticles are gaining increasing attention due to their biological and medical applications. In this letter, we experimentally demonstrate an optical manipulation of 250-nm-diameter gold nanoparticles along an optical nanofiber (550 nm in diameter) injected by an 808-nm laser light. The nanoparticles situated in the evanescent optical field are trapped by optical gradient force and move along the direction of light propagation due to optical scattering force. The velocities reach as high as 132 μm/s at an optical power of 80 mW.