Achromatic self-imaging with finite extension light sources

Self-imaging phenomenon has been widely used in many research areas and applications. We investigate how polychromatism joined to finite size of the source affect the self-imaging process. Under some restrictive circumstances, an achromatic and continuous self-imaging regime is produced. An intuitive analytical interpretation of the achromatic behavior in terms of optical paths is presented. These results are useful for a wide range of photonic and technological applications such as optical encoders, interferometry, optical inspection techniques, structured illumination, microscopy, etc. (paper)