Fig. 1: Gradient-thickness-protected WGM microbottle resonator for large-scale particle trapping.
From: Large-scale optical trapping using a gradient-thickness protected microbottle resonator
a Schematic of particle trapping in the microbottle WGM resonator. b Microscope image of the microbottle, overlaid with simulated optical hotspots near the inner wall. c Zoomed-in rz-view of the optical hotspots at equatorial center, showing the action of the optical gradient force. d xy-view showing the action of the optical scattering force
