Comparison of trap stiffness between a Solid Mode Optical Trap and a Do-nut Mode Optical Trap

Abstract

Do-nut Mode Optical Trap is the kind of Optical Trap that the laser distribution in the center part of the beam is approximately zero. Because the trapping effect of an Optical Trap correlates closely with the distribution of optical field, the scattering force of Do-nut Mode Optical Trap is markedly reduced. We realized Do-nut Mode Optical Trap by rebuilding wave front. Then we studied the trapping effect and trap stiffness of Solid Mode Optical Trap and Do-nut Mode Optical Trap in the cases of upright microscope and inverted microscope. We measured the stiffness of the Optical Trap near the focus with Boltzmann statistics method. The distribution of the optical field of Do-nut Optical Trap is like aura. And the trapping effect changes with the diameter ratio of the aura.