Fabrication of Diffractive Waveplates by Scanning Wave Photopolymerization with Digital Light Processor

Liquid-crystalline materials with precise molecular orientation patterns have attracted much attention due to their potential application to diffractive waveplates by utilizing their optical anisotropy. However, even by the most sophisticated photoalignment processes, the control of large-area molecular orientation patterns remains a challenge due to the need of a fine spatial control of polarization state of incident light or light interference. Recently, we have developed a photoalignment method based on a novel concept of scanning wave photopolymerization (SWaP) that enables us to control arbitrary two-dimensional orientation patterns without polarized light. Here, we demonstrate the fabrication of LC polymer films with a cycloidal molecular orientation over a large area by SWaP with a digital light processor, and investigate their unique optical property of the resultant film as a cycloidal diffractive waveplate. SWaP could be an excellent method to provide a new pathway for designing high-performance optical devices.