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In this paper, we present the construction of a trifocal lens system by combining a liquid-crystal (LC) lens and an ordinary lens. The focusing properties of the proposed system can be controlled by changing the polarization state of the incident light wave. The characteristics of the fabricated lens system were evaluated and it was confirmed that the system converged light at three focal points. It was also confirmed that the intensity of the light collected at each focal point could be regulated by controlling the polarization state of incident light and the retardation of the LC Fresnel lens in the proposed trifocal lens system.

A novel, to the best of our knowledge, method for circular-polarization imaging with white light is presented. The vital optical elements of the proposed system are two polarization gratings (PGs) and a wedge prism. The chromatic dispersion of the PG diffraction angle is compensated by the difference of the grating period for the two PGs. In addition, the distance between the diffracted lights on the imaging plane is controlled by using a wedge prism. As a result, S 3 of the Stokes parameter, including the wavelength dependence of a scarab beetle, was observed at a time, and the S 3 contribution to each color was determined by using the color filter of the light-receiving element. Because the white-light polarization image includes a lot of information about the illuminated structure, the proposed method should be applied to biomedical sensing and remote sensing.

An aerial display scheme consisting of an orthogonal circular polarization grating (OCPG), a waveplate, a retroreflector array (RRA), and a right-angle prism (RAP) was developed. Because of the OCPG’s functionality, retroreflected light from the RRA is transmitted through the RAP boundary surface by avoiding the total reflection condition. The proposed system can potentially increase optical throughput to 100% by designing the boundary surface incidence angle to be Brewster’s angle. The scheme’s feasibility was demonstrated experimentally using an OCPG and waveplate that were fabricated from polymer liquid crystal with optical anisotropy using a photoalignment technique. The scheme should be used as a type of aerial display that is compatible with polarization-diffractive elements called Pancharatnam–Berry phase elements.

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