This paper presents a preliminary study of combining the Schwarzschild pair of mirrors with lenses of fused quartz and fluorite to obtain an ultraviolet microscope objective. It is found that the catadioptric Schwarzschild objective is superior to the catadioptric Newtonian objectives described in Paper I.
An objective using spherical surfaces and corrected from 220 mµ into the near infra-red is described. The obscuring ratio of this objective is 7 percent in area at NA 1.1.
DAVID S. GREY, "A New Series of Microscope Objectives: II. Preliminary Investigation of Catadioptric Schwarzschild Systems," J. Opt. Soc. Am. 39, 723-728 (1949)