Laser Guidance and Trapping of Mesoscale Particles in Hollow-Core Optical Fibers

Mesoscale particles are guided and trapped in micron-sized hollow optical fibers using a $\frac{1}{2}-\mathrm{W}$ near-infrared diode laser. The optical scattering force calculated using geometrical ray optics is $3\times {10}^{-11\mathrm{}}\mathrm{N}$ for a $7-\mu \mathrm{m}$ polystyrene sphere, and agrees well with velocity measurements of optically guided spheres in water. We have levitated a variety of particles using laser-fiber guidance, and have mixed micron-sized glycerin droplets in two-beam laser-fiber traps.