Fig. 5.

Polarization-dependent dynamics. (A) Electron micrographs of a NW before and after a laser pulse whose E-field polarization is parallel to the long axis of the NW. (Scale bar, 100 nm.) (B) Electron micrographs of a NW before and after a laser pulse, but with a perpendicular E-field polarization. (Scale bar, 100 nm.) A and B, Center and Right correspond to the images at different laser fluences (unit is mJ/cm²). The circles indicate the morphological change of the top bead. (C) Length reduction of the GaAs NWs at different polarization directions. For each polarization, the laser fluence is 13 mJ/cm². The length reduction was determined from the NW length change after each laser shot. (C, Inset) Schematic diagram showing a NW excited by a laser pulse with its E-field polarization parallel or perpendicular to the long axis of the NW.