| 초록 |
Photonic crystals (PCs) have been widely used in anti-counterfeiting purposes due to their beautiful and diverse color change. For example, depending on the viewing angle, the reflection color of PCs is changed, and thus it is currently used in many bills. Here, we demonstrated a new type of anti-counterfeiting code whose color changes depending on the light's polarization state. Chiral PCs with optical activity were used to rotate the linearly polarized light, and the transmission color was changed dramatically, which can be detected with two plastic polarizers in real-time. To realize the system, helical nanofilament liquid crystal phase has been studied, including its alignment method and chiro-optical properties. As this is the unique functionality only possible in chiral PCs, this can be used as advanced anti-counterfeiting technology, which cannot be imitated easily with conventional PCs. |
