Design, Fabrication, and Characterization of Tunable Cat's Eye Retroreflector Arrays as Optical Identification Tags

This study has developed an independently-addressed tunable cat´s eye retroreflector array for an optical identification system. Switchable cat´s eye retroreflectors are achieved by incorporating polymer dispersed liquid crystal film and indium tin oxide (ITO) electrodes into the cat´s eye structure. Experiments show that the gap between the front and back units of the cat´s eye retroreflector plays a role in the optical performance of the device. The second-generation device is used to realize the optical ID tag. By controlling the ON-OFF state of each pixel, the tunable optical device can generate a dynamic image which carries temporal and spatial codes for the purpose of identification. The ID tag (cat´s eye retroreflector array) can operate at two orientations.