Fig. 2: Optical pushing and pulling of a droplet with a same nanofibre.
From: Ultra-long-range optical pulling with an optical nanofibre
a Schematic of the experimental setup. EDFA, erbium-doped optical fibre amplifier. Top-view time-sequential optical microscope images of forward (b) and backward (c) motions of a 20-μm-diameter silicone-oil droplet along a 373-nm-diameter silica nanofibre. The power of the driving light (Pin) is 0.1 W for the 980-nm-wavelength light in (b) and 0.05 W for the 1552-nm-wavelength light in (c), respectively. Note that in (b), the 980-nm-wavelength light is scattered by the droplet and observed by the CCD camera in the far-field. Scale bars, 20 μm (b, c). d Measured droplet velocity (hollow circles) with different Pin, λ0 and droplet diameters d, showing good consistency with the calculated results (solid lines). The error bars denote standard deviations of the measured velocity.
