Catoptric lens i.e. four mirror lens, for imaging scan line, in laser scanning microscope, has mirror group displaying linear object field in meridional plane in intermediate image, and another group displaying intermediate image

摘要

The lens has a mirror group, which displays a linear object field of a linear object (10) in a meridional plane in an intermediate image. Another mirror group displays intermediate image in an image field, and the mirror group comprises a mirror i.e. free-form mirror. The lens comprises a distortion in an image plane, and a free-form surface i.e. spline surface is formed by a polynomial development. The lens has an image-sided numerical aperture in a sagittal plane.