Mode division multiplexing for multiple particles noncontact simultaneous trap.

We propose and demonstrate an optical trap on the basis of a normal single-mode fiber (SMF), which is used to trap two particles in the axial direction at the same time without contact based on mode division multiplexing technology. We design and manufacture a tapered fiber probe. The mode beam is excited by docking a normal SMF to a 980 nm SMF with a 2 µm offset. Then the beams of and are both transmitted in the fiber. To converge the mode beam, a SMF with a tapered end is used to produce a cage for trapping the first microparticle. This particle acts as a lens to converge the mode beam to trap the second microparticle. We verify the feasibility of trapping two particles simultaneously through simulation. With this function, the proposed optical trap is easier to manipulate different individual particles for comparison and testing, which can promote the development of the biological, biophysical, colloidal, and soft matter fields.