Optical system with electronic spot size control and focus control optics

摘要

An illumination system includes optics capable of adjusting the size of a beam of light and adjusting the focus of the beam of light. Spot size control optics adjusts the lateral extent of the beam of light. Light from the spot size control optics passes to focus control optics that control the focus of the beam of light. The beam of light focussed by the focus control optics has a first focus position for a first lateral component of the beam of light and a second focus position for a second lateral component of the beam of light, the first and second lateral components being perpendicular. The focus control optics adjust the first focus position to a greater axial extent than the second focus position. Actuators adjust the focus control optics.