Formation of twisted Au microstructures by optical vortex pulse irradiation

The formation of a twisted Au microstructure was demonstrated by irradiating the Au thin film with a focused optical vortex laser pulse. The theoretically calculated torque generated by optical radiation force of optical vortex was confirmed to be consistent with the twist direction of the experimental results. The microstructures formed by changing the focal position were experimentally investigated. Through simulations, it was shown that the spherical wave of the focused beam may affect the distribution of the optical radiation force at the defocus positions.