High aspect ratio line shapes generated with a diffractive/refractive hybrid approach

摘要

High aspect ratio line shapes can be generated using a diffractive remapping beam shaper and a refractive cylinder lens. A typical line shape is 10 mm in the long uniform axis and 0.05 mm or less in the Gaussian axis. The use of a TEM_(00) allows for a diffraction limited short axis focus while expanding to sizes of greater than 100 mm in the uniform direction. In applications that require scanning, the Gaussian axis is perpendicular to the scan direction and the uniform axis is parallel to the scan direction resulting in a uniform (time averaged ) illumination in both axis. Many laser users throw away > 50 % of their laser power to achieve these line shapes, while using this diffractive/refractive hybrid approach > 90 % of the total input energy can be utilized.