Bilinear noncoherent imaging of patterns on translucent scattering substrates

Abstract

We treat the imaging of thin absorbing patterns on translucent substrates that are noncoherently illuminated from the side of the imaging lens. Examples of such objects are circuitry on ceramic and ink on paper. With a translucent substrate, the thin-object approximation commonly used in the theory of image formation is invalid, even if the surface pattern is thin. In the process of image formation, part of the incoming light passes through the surface pattern and penetrates into the substrate. The light is scattered, and a portion returns to the surface and passes again through the pattern. The image formed from this light depends linearly on the scattering characteristics of the substrate and bilinearly on the transmittance of the pattern. © 1984 Optical Society of America.