Optical vortex induced chiral mass-transport of azo-polymer through two photon absorption

We discover that 1.06 μm picosecond vortex pulses induce chiral mass-transport to form a single-armed chiral surface relief in azo-polymer through two photon absorption process. The surface relief exhibits a diameter of a 2.5μm, i.e. 0.7 times of diffraction limit.