Fig. 1. Principle of an ultra-high NA meta-fibre for flexible optical trapping.
a Illustration of the device including a 3D nanoprinted meta-lens located on the tip of an optical fibre to trap particles. b Example of a measured radial focal plane in water (scale bar: 500 nm, wavelength of 660 nm, the dashed line indicates the width of the fitted Airy function). c Micrograph of a 2 µm silica bead and (d) an Escherichia coli (E. coli) bacterium optically trapped with a single fibre UNM in water imaged from the side (scale bars 15 µm)