Multi-destination release of nanoparticles using an optical nanofiber assisted by a barrier

This work provides optical delivery and controllable multi-destination release of nanoparticles (NPs) using a defect-decorated optical nanofiber (NF) assisted by a barrier. The delivery and release was accurately controlled using different evanescent optical fields at different regions of the NF by changing the injected optical power. The NPs (polystyrene, 713 nm diameter) were delivered along the NF (690 nm diameter) toward the decorated defect when a laser beam at a wavelength of 980 nm was injected into the NF. At an injected optical power of 25 mW, the NPs were delivered at an average velocity of 2.9 μm/s and 90% of them were released around the barrier, which is set beside the defect. When the power was increased to 40 mW, the average delivery velocity reached 4.2 μm/s and 92% of the NPs were released at the side of the defect opposite to the barrier. By further increasing the power to 80 mW, the average delivery velocity further increased to 8.2 μm/s. Consequently, 90% of the NPs moved across the defect and were delivered to the next destination at an average velocity of 5.2 μm/s. The experimental results were then explained theoretically using numerical simulations.