Recent Progress in Microscope Objective Design and Optical Material

Abstract

As the use of microphotographs has increased in modern microscopy, plan-apochromat objectives are indispensable that have well-corrected field curvature and no secondary spectrum over wide wave-length range. But, the correction of the field curvature and the elimination of secondary spectrum are apt to conflict each other, so designing the plan-apochromats is painful task. In this paper, the importance of adequate use of the materials with extraordinary partial dispersion is discussed using a simple thin-lens model.