Single Fiber Optical Tweezer for Particles Multi-Dimensional Arrangement

We propose and demonstrate a single fiber optical tweezer for particle multi-dimensional arrangement based on an optical bottle beam produced by concatenating a few-mode fiber and a step-index multimode fiber. We use the mode division multiplexing technology to produce the optical bottle beam with uneven energy distribution. The LP₁₁ and LP₂₁ mode beams are excited by docking a 980 nm single-mode fiber at the outlet of the light source to a few-mode fiber with a defined offset. The few-mode fiber allows LP₀₁, LP₁₁, and LP₂₁ mode beams to be spread in. The optical bottle beam is focused on a high refractive index glass microsphere integrated on the fiber end. The LP₀₁ mode beam is used to trap particles and array them in a one-dimension space (linear arrangement), the LP₀₁ and LP₁₁ mode beams are used to trap and array particles in a two-dimension space (planar arrangement), and the LP₀₁, LP₁₁, and LP₂₁ mode beams are used to trap and array particles in a three-dimension space (solid arrangement). The proposed fiber optical tweezer is simple in structure and will allow us to examine the interaction between the cells when held in close proximity.