| 摘要 |
<p>A laser system (1) for producing a line beam laser output (4) comprises a laser source (6), and a lens system (12) for modifying the intensity profile of the incident laser input, and comprising a plurality of lens elements (16) arranged at a predetermined lens pitch. An optical filter (9) is provided between the laser source (6) and the lens system (12), the filter comprising transmissive portions (42) and opaque portions (44). The transmissive portions (42) define a repeating pattern (46) with a pitch corresponding to the lens pitch. The optical filter (9) modifies the input to the lens system (12) such that the output of the lens system gives rise to a desired intensity profile at the output of the laser system (1). This desired profile can have a tapered profile at the top of the hat, which gives improved performance for laser crystallization. The invention can be implemented with minimum adaptation of an existing top hat profile laser system.</p> |
