Coherent, Inc.

Coherent Lasersystems Gmbh & Co. Kg

Frank Simon

Ludwig Schwenger

Paul Van Der Wilt

Andrea Caprara

Thomas Schroeder

Elko Bergmann

Thomas Wenzel

Roman Windpassinger

Holger Graefe

Uwe Wiedenbruch

A beam homogenizer for transforming a beam of laser-radiation into a flat-top intensity distribution having brighter or darker edges comprises a first lens array, a second lens array, and a positive lens. The first lens array includes a plurality of lens elements that are separated by gaps having no optical power. Brighter or darker edges are produced by selecting a distance between the first and second lens arrays that is less than or greater than the focal length of lens elements in the second lens array.

Apparatus for forming a homogeneous intensity distribution with bright or dark edges

In a laser line projection apparatus, six spaced-apart unpolarized laser-beams are plane-polarized with low loss by a combination of a thin-film polarizer, a reflector, and two polarization rotators. Two beams are polarized in each of three polarization-orientations. Two of the polarization-orientations are orthogonally aligned with each other in P and S orientations. The other polarization-orientation is non-orthogonally aligned in an intermediate orientation. The beams are intensity-homogenized and projected into a line of radiation. Any point on the line of radiation is formed from rays with an angular distribution of polarization-orientation from S to P through the intermediate orientation and back to S through the intermediate orientation.

Polarization-controlled laser line-projector

Apparatus for homogenizing and projecting two laser-beams is arranged such that the projected homogenized beams are aligned parallel to each other in a first transverse axis and partially overlap in second transverse axis perpendicular to the first transverse axis. The projected homogenized laser-beams have different intensities in the second axis and the degree of partial overlap is selected such that the combined intensity of the laser beams in the second axis has a step profile.

Excimer laser apparatus projecting a beam with a selectively variable short-axis beam profile

The present invention provides laser beam micro-smoothing for laser annealing systems. Laser beam micro-smoothing comprises shifting a laser beam in the direction perpendicular to the scanning direction (y) of a laser annealing system, while holding the laser beam fixed in the direction of scanning (x). The shifting may be accomplished, for example, with a pair of micro-smoothing mirrors. The shifting smoothes out small-scale inhomogeneities in the profile of the laser beam and prevents microscopic stripes associated with prior art laser annealing systems. Because the shifting occurs only in the direction perpendicular to the scanning direction (y), the laser annealing process in not adversely affected.

Laser beam micro-smoothing

In a photomask projection system, a photomask mask is illuminated by light from two lasers. A beam from one of the lasers is mixed with a beam from the other laser to provide two mixed beams each containing of portion of the beams from both lasers. The mixed beams are directed at an angle to each other and intersect on the photomask.

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Goettingen, Germany

Frank Simon