OPTICAL ILLUMINATION APPARATUS FOR ILLUMINATING A SAMPLE WITH A LINE BEAM

摘要

An optical system for illuminating a sample with a line beam comprises a light source (24), a beam shaper (30) for transforming the beam of light emitted by the light source into an intermediate astigmatic image and an imaging system for transforming the intermediate astigmatic image into a final astigmatic image and for illuminating the sample. The beam shaper provides different non-unity magnifications in a lateral plane and in a transversal plane, and comprises a toroidal entrance surface for implementing the angular magnification and angular reduction and a toroidal exit surface with finite radii of curvature. The invention enables the use of existing beam shaping apparatus, normally used to make a light output have a more circular cross section, in combination with the imaging system, in order to provide line beam illumination of a sample.