LIGHT BEAM SPOT SHAPE MODIFICATION WITH FULL PUSH-PULL FUNCTIONALITY

摘要

The present invention generally relates to a method for modifying the spot shape of a focused light beam. More specifically, the invention relates to a method for enlarging the spot of a focused light beam in such way that full push- pull functionality is kept. The invention further relates to an optical element suitable for realizing the modification of the spot shape of the focused light beam, and to an apparatus for reading from and/or writing to optical recording media using such method or optical element. According to the invention, a special phase distribution is applied to the light beam (1), which acts like a grating and splits the light beam (1) into several orders.