3D-vision systems

ABSTRACT Increasing demands in the areas of machine, computer and robot vision strongly motivate the renovation of optical sensingdevices. Based on the physical effect of Frustrated Total Reflection (FTR), the essence of this paper deals with the new designof optical modulators used in 3D-vision systems. Optical modulators commercially available do not meet some extendedrequirements for 3D applications. However, the device presented in this paper permits the specifications of optical 3D-measurement techniques like accuracy; robustness, compactness as well as fastness to be realised with higher capabilities.For this purpose, we suggest two different types of optical 2D mixers. Both are intended to explore the FTR effect tomodulate light in a large aperture with minimal image aberration. In one case an air gap between media of higher dense ismodulated by an il-voltage applied to a piezo crystal as an rf-controlled tuning medium. In the other case the variation of thegap or modulation is achieved by using a surface acoustic wave device which acts as a surface grating medium due to theeffect of a travelling periodic comigation. The integrated optical components play a substantial role for the optical modulationand imaging.Some simulation results of this optical devices show that the inherent non-linearity of the FTR modulator may beneglected in practical applications, thus yielding a high modulation depth. Furthermore, a 3D-image system adapting thismodulation optics is also depicted in the paper.Keywords: optical modulation, 2D mixer, 3D-vision, large aperture, FTR effect, acoustic wave device, piezo electric device.