Design aspects of planapochromatically corrected microscope objectives for reflected light applications

Making an object with extreme weak surface structures well visible is always a challenge for microscope systems in reflection mode. The demands on materials microscopy for the faithful, high-contrast depiction of extremely small object details mean, that microscope objectives must be corrected down to the refraction limit over the whole field of view. Due to their influences on image contrast, the below mentioned aspects must be considered by the design. 1. Correction of aberrations up to edge of the field 2. Minimization of stray light and optimization of transmission 3. Telecentricity of illumination and of the image forming ray bundles 4. Considerations of DIC-, POL- and dark field applications These requirements are typical in the field of material microscopy.