Diffractive-optics-based sensor for simultaneous inspection of reflected and transmitted light from porous materials

Optical reflectance and transmittance of porous material carry information from a surface smoothness and a bulk porosity of a sample. Thus it is of great importance to get simultaneously optical signals connected with the reflected and transmitted light from a porous sample. Previously we have showed that a diffractive optical element (DOE) based sensor is capable to distinguish optical signals, when a scattered wavefront from a sample surface is diffracted through a DOE-aperture, with good agreement compared with the values drawn out by a conventional spectrophotometer. The aim of this paper is to present a DOE based sensor for simultaneous inspection of reflected and transmitted light from porous materials, which are e.g. wood, paper, and pharmaceutical compacts.