Fig. 1. Schematic layout of the experimental apparatus.

Fig. 2. Scanning electron microscope image of a selectively chemically etched conical tapered Fibercore Inc. probe tip showing a hollow central region.

Fig. 3. NSOM beam scans and section analysis at the output of an uncoated hollow-tipped Fibercore Inc. probe in air using an unpolarized λ=633nm He-Ne laser. The NSOM probe aperture was 140 nm. The NSOM beam scans were made at heights of (a) 0 nm, (b) 420 nm, (c) 1120 nm and (d) 1960 nm above the probe tip exit surface. The distance between the red markers is ≈1.9 µm.

Fig. 4. (2.5Mb) Real-time movie showing 3-D trapping of a 2µm diameter solid glass bead in water using a single selectively etched ≈20µm diameter hollow tipped fiber probe. The λ=1.32 µm laser power coupled into the fiber was ≈10mW. The direction of gravity is into the screen. The video shows that when the laser beam was blocked the bead moves back to the fiber. When the laser beam was unblocked the bead quickly (fraction of a second) moved to the 1µm tip to bead separation. The remainder of the video shows the fiber probe and bead being translated in the water at speeds of ≈20 µm/s. The video clip moves around and is somewhat noisy since a video camcorder was used to record the signal from a monitor.