The Specimen Illumination Path and Its Effect on Image Quality

The unique imaging properties of all confocal microscope systems are based on the fundamental condition that the illumination and collection (detection) optical paths contribute equally to the formation of the final image. However, many of the optical and imaging properties of confocal microscopes can be analyzed effectively by considering the illumination and detection paths to be two distinct entities. In this chapter, we explore one of these optical paths—the illumination path—and describe the ideal function and practical limitations of the total path and the optical components therein. Several other chapters in this volume present additional specific information concerning some of these optical components (e.g., light sources, intermediate optics, objective lenses). Our purpose is to treat the illumination path as an integral system and describe its contribution to the overall performance of the confocal microscope.