Patent ID: 7006549

Claim:
A method for combining M laser-radiation beam groups with N laser radiation beam groups where M and N are integers greater than one, each of the groups including at least two beams spaced apart and parallel to each other, the M beam groups being parallel to each other and spaced apart by a distance V, and the N beam groups being parallel to each other and spaced apart by a distance V, the method comprising: providing a beam combiner including a plurality of reflective strips in a beam combiner plane, spaced apart and parallel to each other, with transparent regions between adjacent said reflective strips; directing said M beam groups onto said beam combiner at a first non-normal incidence angle to said beam combiner plane such that said beam groups pass through said beam combiner plane without being intercepted by said reflective strips and with one or more of said M beam groups passing through a said transparent region, said M beams exiting said beam combiner in a propagation direction; and directing said N beam groups onto said beam combiner at a second non-normal incidence angle to said beam combiner plane such that said beam groups thereof are reflected by said reflective strips, said beam groups being aligned with said beam combiner and said second non normal incidence angle being selected such that said N beam groups are reflected by said reflective strips in said propagation direction, thereby providing M+N beam groups propagating parallel to each other and spaced apart by a distance less than V wherein said reflective strips of said beam combiner are deposited on a transparent optical element having opposite surfaces parallel to each other, and wherein said first and second incidence angles are equal.