We report a method to optically trap and micromanipulate metallic particles using IR laser. The experiment demonstrates
the trapping of metallic particle using low NA objective lens (0.6 N.A). Unlike single beam gradient trapping of
dielectric objects, the optical trapping of metallic particles occurs due to diffraction effect. We thus provide evidence for
non-gradient forces playing a dominant role in the trapping of metallic particles, in here for the case of 3μm Fe particles,
efficient trapping occurs at off-axis position (in the side lobes) of a focused laser beam. The optical trap is characterized
by measuring the external magnetic field required to dislodge the Fe particle, and was found to be 0.03T to 0.11T for
laser power 5 to 55mW at the sample.