| 摘要 |
An apparatus for and a method of forming a plurality of groups of laser beams (2, 2′, 2″) are defined. Each group (2, 2′, 2″) may comprise two or more laser beams. The apparatus comprises a first diffractive optical element (3, referred as DOE) and a second diffractive optical element (8), the first DOE (3) being arranged to receive a first laser beam (1) and to divide this into a plurality of second laser sub-beams and the second DOE (8) being arranged to receive said plurality of second laser sub-beams and to divide each of these into two or more groups of third laser sub-beams (2, 2′, 2″), the separation of the groups in a direction perpendicular to a first axis being adjustable by rotation of the first DOE (3) about its optical axis and the separation of the third laser sub-beams (2, 2′, 2″) within each group in a direction perpendicular to the first axis being adjustable by rotation of the second DOE (8) about its optical axis. |
