Design of micro-optical tweezers

Conventional optical fiber tweezers are unsuitable for operation inside cells, due to their big-size fiber tip to realize beam focusing. In this letter, new micro-optical tweezers with no focusing are demonstrated, which only demand a uniform thin-fiber to realize 3D capture and manipulation. The fused biconical taper method is adopted to produce micro-optical tweezers with a diameter of 0.75 mu m, the finite-difference time-domain (FDTD) calculation method is used in the simulation and in the discussion of trapping ability, and the possibility of using this method is confirmed with experiments. These optical tweezers have a small size, tight structure, and simple production method, and it is hoped that they will become an effective tool in cell capture and manipulation.