Beam shaping with multiple-powered phase masks

Abstract

We present multiple-powered phase masks to convert a plane wave beam into different shaped beams. With the squared phase mask, a hollow beam is obtained before the Fourier plane of the converging lens and a highly focused beam is obtained after the Fourier plane. With the fourth-power phase mask, a crosshair beam with highly focused point in the center is formed on the Fourier plane, then a beam lattice with strong light spots on the four corners is generated after the Fourier plane and the beam lattice has different size on different observing distances. With the fifth-power phase mask, a self-bending beam is generated over long propagation distances.