Polarization-Encoded Multicolor Retroreflective Graphics composed of Geometrically Tailored Hemicylindrical Microstructures
발표자
이지우 (카이스트)
연구책임자
김신현 (카이스트)
공동저자
이지우 (카이스트), 김신현 (카이스트)
초록
내용
Concave curved microstructures facilitate retroreflection through total internal reflection (TIR) at their inner surfaces. When light is incident on the concave side, interference occurs between optical paths that, despite having identical reflection angles, differ in path length due to the varied number of internal reflections. This phenomenon results in the emergence of distinct structural colors. In this study, we fabricated semi-cylindrical microstructures using an one-step photolithography and thermal reflow process. We observed that these semi-cylindrical forms, in contrast to conventional hemispherical ones, possess optical anisotropy governed by the incident and reflection angles. Moreover, the phase shift induced by TIR introduces polarization-dependent anisotropy visible under crossed polarizers. Utilizing these unique characteristics, we developed retroreflective multicolor graphics that reveal different visual information based on the polarizer’s orientation.