Laguerre-Gaussian beam generated with a multilevel spiral phase plate for high intensity laser pulses

We investigated an Laguerre-Gaussian (LG) beam that can carry an orbital angular momentum and has a doughnut-shaped intensity pattern. We developed a multilevel spiral phase plate (SPP) that generates an LG beam by applying the wave surface of a spiral structure directly to a Gaussian beam for application to microscopic laser material processing. We experimentally demonstrate, for the first time, that it is possible to generate an LG beam with the multilevel SPP that allows the use in high intensity laser pulses. (C) 2004 Optical Society of America.